The function(s) listed below. Some instruments have multiple functions - for example, the 4195A is a VNA, spectrum analyzer and an impedance analyzer. Therefore the 4195A is listed in multiple categories
Went to great lengths to create PyVISA program to read using the GPIB the x4 parameter S-parameter data from the HP8510C. This eventually would read consecutive 1701 point sweeps in a round 5 seconds using the HP binary data format; ASCII data formate took much longer. That was for uncalibrated data. However, when i tried to read TRL calibrated data it would take over two minutes to read the data. The obvious solution then would be to just read the uncalibrated data and perform the TRL calibration in the PC. I could trawl through endless papers to find a suitable mathematical equations to code up in Python. From what i gather, mathematically its quite complicated, solving something like 12 simultaneous equation, clearly doable, but i've also got a massive list of other stuff to do. Might anyone have an algorithm to perfor the TRL calibration, or know where i might find this?
I need some help for my HP 3325A, which worked many years perfect, but know has the common FAIL 2 & 3 Error. (PASS 1, FAIL 2 FAIL 3)
?
It has still sin, square and triangle output, the amplitude is ok, the range is ok (1-10Vpp) into a 50 Ohm load.
When swtichting from sin to square or triangle the a-cal error message comes up.
?
The voltages are good, 5.05, -15.16, +15.16 volts, no ripple, or minor. I changes some caps in the psu some time ago.
?
The integrator output looks good, the voltages are as expected on the testpoints LVL,OS1,OS2,AMPL,XDR. I interchanged already U20 & U24.
?
I have a revision C board, the realays on the att board are the flat black ones.
?
Alls tests were done grounding the ACD pin, 1khz and 10Vpp.
?
I found something strange in the amp section. placing the jumper to detach the amp from AMP IN and measuring the DC bias voltage at F3 left and right it shows -12.73 volts.
Should be +7.5 volts.? When toggeling the jumper and playing with the amp settings, the voltage sudden comes to a normal value and I could adjust the bias with the pot to 7.5 volts.
?
Should it be in any case 7.5 volts after power on and? when AMP in pin is disconnected and with any amp setting?
?
I checked already soldering and diodes, resistors, fuses and caps for shorts.?? And some transitors in the amp section.
?
I have the service manual, there is a huge section testing with a signature analyzer, but I don't have one.
?
So are there any hints, what to test / check next? Am I right in the amp section?
The "grounded soldering iron shorting the battery" is one I know from the HP3478A DMM. They loose their cal data if you do that. It is not a generic problem but certainly something to pay attention to before working on an instrument. Check, than do.
Fortunately, the PS troubleshooting section (p.6-21) has some good directions on how to check the PS once detached from the modules it supplies. It involves loading only the 5.2V output (with a 2ohms/25W resistor). That should provide a determination on whether the -12V rail is loaded down by a module (figuring out what exactly loads it is another issue, given the lack of schematics, and per block diagram I can only tell the -12V goes to the main board), or there's a fault inside the PS itself.?
There's also a fair section on assemblies removal. Will come in handy, given the mainboard needs to come off. Still not the best SM I've seen by HP standards.?
On Thu, Feb 27, 2025 at 4:34?PM Peter Gottlieb via <hpnpilot=[email protected]> wrote:
You are seeing the tabs which are spot welded to the cell, it's not a socket,
the cell is soldered to the board.? Well you might be able to pry but risk
damage to the board or traces.? At this point replace the thing.? Best is to
desolder it from the bottom of the board.? Definitely figure out what's up with
that power supply though.
Peter
On 2/27/2025 2:32 PM, Radu Bogdan Dicher via wrote:
> I lifted today the CRT card, just enough to have some access to the battery,
> but I'm still unsure how it's supposed to come off. I tried prying the top
> spring "leaf," but it seems attached (possibly soldered) to the battery - or
> is that a top lid over the battery? And then there's a piece of foam
> underneath, possibly double-sided sticking. I'd rather not remove the whole
> mainboard just to replace this, but I don't think I can try many more prying
> and pulling before?I risk something more serious due to the lack of access.
>
> Hoping someone having done this before?recognizes the type of battery and its
> socket from the enclosed pictures?and has some good pointers. I am not seeing
> any other battery on this board - I was expecting?a bigger, cylindrical?type,
> but I think this must be it for the 54512B.
>
> Thanks a bunch in advance.
> Radu.
>
> On Wed, Feb 26, 2025 at 7:08?AM Radu Bogdan Dicher via
> <> <vondicher=[email protected]> wrote:
>
>? ? ?Thanks, Jim. I still have to perform that test where I play The Cure from
>? ? ?my garage with the door open, which?I'm sure you'd hear from your bench!!
>? ? ?;))))
>
>? ? ?I tried?to pry off the battery this morning without further disassembly,
>? ? ?but it doesn't want to come off that easily. There seems to be a blob of
>? ? ?solder - has anyone seen that before? - on top of the holder, and some
>? ? ?sort of?foam?tape below it. Maybe I need to apply force a little bit
>? ? ?differently.
>
>? ? ?Unless there's some secret?regarding how to remove the battery, I'll have
>? ? ?to at least remove at least the CRT module to gain?better access to it. I
>? ? ?really think access to a battery - even one guaranteed?a decade - should
>? ? ?be easier than this. So this should be possible later in the week when I
>? ? ?have more time.
>? ? ?Radu.
>
>? ? ?On Wed, Feb 26, 2025 at 5:38?AM Jim Ford via <>
>? ? ?<james.ford=[email protected]> wrote:
>
>? ? ? ? ?Speaking of CR2032 coin cells, don’t spend $$ at a local store; order
>? ? ? ? ?from Digital-Key for about $0.50 in quantity.? I usually buy 50 pieces
>? ? ? ? ?at a time.? But then I have a keychain LED flashlight (torch for the
>? ? ? ? ?Brits) that my kids bought me some years ago (best gift ever!) that
>? ? ? ? ?takes 2 cells and a 3-LED baseball cap that I wear when walking my
>? ? ? ? ?dogs at night that takes 4.? So I go through a lot of them.? Mouser
>? ? ? ? ?might have them as well.? I’ve not ordered from D-K for a while
>? ? ? ? ?because they buried the big product table, and it seems like something
>? ? ? ? ?else they did got me PO’d at them.? HTH.
>
>? ? ? ? ?Jim Ford
>? ? ? ? ?Laguna Hills, California, USA
>? ? ? ? ?> On Feb 25, 2025, at 7:46?PM, Peter Gottlieb via
>? ? ? ? ?<> <hpnpilot=[email protected]> wrote:
>? ? ? ? ?>
>? ? ? ? ?> ?CR followed by numbers indicates the physical size, CR2032 etc.? I
>? ? ? ? ?would say if you're already in there, replace them as even if they are
>? ? ? ? ?good they won't last much longer.? I always replace memory hold up
>? ? ? ? ?cells in anything that crosses my bench.? Low hanging fruit.
>? ? ? ? ?>
>? ? ? ? ?> The power supply might be low because of an overload caused by a
>? ? ? ? ?shorted capacitor.? Perhaps try unplugging the supply connections. I
>? ? ? ? ?can't remember if that model's supply will run correctly without
>? ? ? ? ?load.? But if you do go inside it, check the capacitors for
>? ? ? ? ?capacitance, leaks and ESR.
>? ? ? ? ?>
>? ? ? ? ?> Peter
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>> On 2/25/2025 9:35 PM, Radu Bogdan Dicher via
>? ? ? ? ?<> wrote:
>? ? ? ? ?>> I've gotten a bit of a chance tonight to check a couple of things
>? ? ? ? ?with one of the units:
>? ? ? ? ?>>
>? ? ? ? ?>> *Unit #2 *(S/N: 3214A00704: consecutive units!)
>? ? ? ? ?>>
>? ? ? ? ?>>? * Voltages on rails:
>? ? ? ? ?>>? ? ? o +11.924V
>? ? ? ? ?>>? ? ? o +12.050V
>? ? ? ? ?>>? ? ? o -3.27V(fluctuating somewhat; no significant ripple on it)
>? ? ? ? ?>>? ? ? o -5.2289V
>? ? ? ? ?>>? ? ? o 3.5285V
>? ? ? ? ?>>? ? ? o 5.2067V
>? ? ? ? ?>>? * There's a coin battery on the main board, which I didn't remove
>? ? ? ? ?yet (I'd
>? ? ? ? ?>>? ? rather measure its voltage before I do, in case it's still good
>? ? ? ? ?and holds
>? ? ? ? ?>>? ? the memory). It's a Panasonic and I can only read "CR..." from
>? ? ? ? ?it. Would
>? ? ? ? ?>>? ? there potentially be more harm done by removing it, than simply
>? ? ? ? ?losing the
>? ? ? ? ?>>? ? cal constants, in case it's still good for some reason? I'm
>? ? ? ? ?thinking of
>? ? ? ? ?>>? ? biting the bullet and removing it, replacing it, and then seeing
>? ? ? ? ?where
>? ? ? ? ?>>? ? that takes me.
>? ? ? ? ?>>
>? ? ? ? ?>> So this second unit has more issues than just a dead battery (in
>? ? ? ? ?case the latter checks out). I'll have to remove the power supply
>? ? ? ? ?module and see what could be wrong with the -12V rail. I'm
>? ? ? ? ?provisionally blaming the unruly -12V rail for the additional error
>? ? ? ? ?this second unit has, which the first doesn't. So my money's on that
>? ? ? ? ?the first one has a good -12V rail.
>? ? ? ? ?>> Radu.
>? ? ? ? ?>>
>? ? ? ? ?>> On Tue, Feb 25, 2025 at 7:14?AM Radu Bogdan Dicher via
>? ? ? ? ?<> <> <vondicher=[email protected]>
>? ? ? ? ?wrote:
>? ? ? ? ?>>
>? ? ? ? ?>>? ? Awesome, thank you, Peter.
>? ? ? ? ?>>
>? ? ? ? ?>>? ? I wonder if anyone has a fresh recollection of what battery or maybe
>? ? ? ? ?>>? ? battery-backed RAM would be suspect and possibly needed so I'd start
>? ? ? ? ?>>? ? working on an order to have the parts ready by the time I carve
>? ? ? ? ?out some
>? ? ? ? ?>>? ? time to open these. From what I know about these generation scopes,
>? ? ? ? ?>>? ? replacing the battery is probably a good idea anyway. The cal
>? ? ? ? ?constants
>? ? ? ? ?>>? ? seem to be gone, so nothing to lose there.
>? ? ? ? ?>>
>? ? ? ? ?>>? ? I wasn't able to find this information (particularly info on the
>? ? ? ? ?battery)
>? ? ? ? ?>>? ? in the manuals, which I find odd.
>? ? ? ? ?>>? ? Radu.
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>? ? On Tue, Feb 25, 2025 at 5:26?AM Peter Gottlieb via
>? ? ? ? ?<>
>? ? ? ? ?>>? ? <> <hpnpilot=[email protected]> wrote:
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? Seems like you are on the right track. Many HP scopes of
>? ? ? ? ?that era
>? ? ? ? ?>>? ? ? ? lose their
>? ? ? ? ?>>? ? ? ? minds if the memory battery goes dead.
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? Peter
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>? ? ? ? On 2/24/2025 11:09 PM, Radu Bogdan Dicher via
>? ? ? ? ?<>
>? ? ? ? ?>>? ? ? ? <> wrote:
>? ? ? ? ?>>? ? ? ? > Hi all,
>? ? ? ? ?>>? ? ? ? > Over the weekend I've got a couple of 54512Bs at my desk
>? ? ? ? ?to seek to
>? ? ? ? ?>>? ? ? ? bring back
>? ? ? ? ?>>? ? ? ? > to full functionality. My main scope is a 54522A, and I
>? ? ? ? ?assume they
>? ? ? ? ?>>? ? ? ? have some
>? ? ? ? ?>>? ? ? ? > commonalities, but I've yet to open mine (it came to me fully
>? ? ? ? ?>>? ? ? ? refurbished and
>? ? ? ? ?>>? ? ? ? > never needed to open the case). I'm not very familiar with
>? ? ? ? ?this
>? ? ? ? ?>>? ? ? ? other series,
>? ? ? ? ?>>? ? ? ? > and hope on some good input and recommendations.
>? ? ? ? ?>>? ? ? ? > The documentation is not as good as others I've seen from HP.
>? ? ? ? ?>>? ? ? ? Specifically for
>? ? ? ? ?>>? ? ? ? > this unit (54512B), Keysight only seems to have a very
>? ? ? ? ?skinny (by HP
>? ? ? ? ?>>? ? ? ? > standards) Service Manual which can't honestly be called
>? ? ? ? ?>>? ? ? ? "module-level Service
>? ? ? ? ?>>? ? ? ? > Manual," as it doesn't really into much detail on the
>? ? ? ? ?different
>? ? ? ? ?>>? ? ? ? modules. Then
>? ? ? ? ?>>? ? ? ? > there's a "Front Panel Reference," which is an odd other
>? ? ? ? ?way of
>? ? ? ? ?>>? ? ? ? naming what I
>? ? ? ? ?>>? ? ? ? > think is the Operating Manual. A couple other manuals have
>? ? ? ? ?to do with
>? ? ? ? ?>>? ? ? ? > programming. That's it.
>? ? ? ? ?>>? ? ? ? > Sometimes in a series you have to look for the main unit,
>? ? ? ? ?but in
>? ? ? ? ?>>? ? ? ? this case I'm
>? ? ? ? ?>>? ? ? ? > not sure that's the 54501A, as the catalog spec sheet seems to
>? ? ? ? ?>>? ? ? ? suggest, or the
>? ? ? ? ?>>? ? ? ? > 54505B, as per the SM. Maybe someone very familiar with
>? ? ? ? ?the series
>? ? ? ? ?>>? ? ? ? would know.
>? ? ? ? ?>>? ? ? ? > Artek doesn't have manuals for the 54512B at all, but they
>? ? ? ? ?do for
>? ? ? ? ?>>? ? ? ? the 54501A,
>? ? ? ? ?>>? ? ? ? > and if applicable, I'd get the series of six manuals they
>? ? ? ? ?sell as a
>? ? ? ? ?>>? ? ? ? bundle. If
>? ? ? ? ?>>? ? ? ? > no go, I'll be a bit in a bind with fixing this given what
>? ? ? ? ?I have at
>? ? ? ? ?>>? ? ? ? hand. I
>? ? ? ? ?>>? ? ? ? > am aware HP was not longer offering component SMs by this
>? ? ? ? ?point,
>? ? ? ? ?>>? ? ? ? though I
>? ? ? ? ?>>? ? ? ? > don't know for a fact on this specific series and scope
>? ? ? ? ?(but I do
>? ? ? ? ?>>? ? ? ? regarding
>? ? ? ? ?>>? ? ? ? > the better?/later? 54522A).
>? ? ? ? ?>>? ? ? ? > Is this really capable of FFT to 500MHz, even if the scope
>? ? ? ? ?is rated
>? ? ? ? ?>>? ? ? ? to 300MHz?
>? ? ? ? ?>>? ? ? ? > I can't make sense of that.
>? ? ? ? ?>>? ? ? ? > Now, on to the specific issues with the units.
>? ? ? ? ?>>? ? ? ? > *Unit #1 *(S/N: 3214A00705)
>? ? ? ? ?>>? ? ? ? >
>? ? ? ? ?>>? ? ? ? >? ?* Upon starting it, it reports something like "TRYING TO
>? ? ? ? ?START
>? ? ? ? ?>>? ? ? ? REALTIME
>? ? ? ? ?>>? ? ? ? >? ? ?CLOCK," which is unsuccessful after a time countdown
>? ? ? ? ?from I
>? ? ? ? ?>>? ? ? ? think 60:
>? ? ? ? ?>>? ? ? ? >? ? ?"REALTIME CLOCK FAILED TO START - DISABLED."
>? ? ? ? ?>>? ? ? ? >? ?* Once I get it to display the default screen and output
>? ? ? ? ?a trace,
>? ? ? ? ?>>? ? ? ? it stated
>? ? ? ? ?>>? ? ? ? >? ? ?"Default cal loaded. Re-cal instrument."
>? ? ? ? ?>>? ? ? ? >? ?* Self Test passes all.
>? ? ? ? ?>>? ? ? ? >? ?* I'm also seeing a solid and apparently accurate 5V
>? ? ? ? ?from the DC
>? ? ? ? ?>>? ? ? ? Cal output
>? ? ? ? ?>>? ? ? ? >? ? ?in the back. I haven't tried the AC Cal output.
>? ? ? ? ?>>? ? ? ? >? ?* Note this one had the Cal switch in the back in the
>? ? ? ? ?UNPROTECTED
>? ? ? ? ?>>? ? ? ? position
>? ? ? ? ?>>? ? ? ? >? ? ?when I got it.
>? ? ? ? ?>>? ? ? ? >? ?* I'm able to display the square wave test signal from
>? ? ? ? ?the front
>? ? ? ? ?>>? ? ? ? panel.
>? ? ? ? ?>>? ? ? ? >
>? ? ? ? ?>>? ? ? ? > *Unit #2 *(S/N: 3214A00704: consecutive units!)
>? ? ? ? ?>>? ? ? ? >
>? ? ? ? ?>>? ? ? ? >? ?* Upon staring it, it stated "CALIBRATION FACTOR
>? ? ? ? ?CHECKSUM ERROR.
>? ? ? ? ?>>? ? ? ? MOVE REAR
>? ? ? ? ?>>? ? ? ? >? ? ?PANEL CAL SWITCH TO UNPROTECTED. POWER INSTRUMENT OFF
>? ? ? ? ?AND THEN
>? ? ? ? ?>>? ? ? ? ON AGAIN.
>? ? ? ? ?>>? ? ? ? >? ? ?RE-CAL INSTRUMENT."
>? ? ? ? ?>>? ? ? ? >? ?* It also says "Trying to start realtime clock (09290)."
>? ? ? ? ?Maybe
>? ? ? ? ?>>? ? ? ? that's an
>? ? ? ? ?>>? ? ? ? >? ? ?error code?
>? ? ? ? ?>>? ? ? ? >? ?* Upon switching the rear Cal switch to UNPROTECTED, it
>? ? ? ? ?boots
>? ? ? ? ?>>? ? ? ? successfully,
>? ? ? ? ?>>? ? ? ? >? ? ?goes to a default measurement screen, but gives me a
>? ? ? ? ?warning "Failed
>? ? ? ? ?>>? ? ? ? >? ? ?interpolar cal." The trace seems to jump around on Y a
>? ? ? ? ?bit.
>? ? ? ? ?>>? ? ? ? >? ?* Self Test passes all /but/ Timebase. It also displays
>? ? ? ? ?the same
>? ? ? ? ?>>? ? ? ? error as
>? ? ? ? ?>>? ? ? ? >? ? ?default screen ("Failed interpolar cal").
>? ? ? ? ?>>? ? ? ? >? ?* 5V out at DC Cal is good.
>? ? ? ? ?>>? ? ? ? >? ?* This one had the Cal switch in UNPROTECTED position,
>? ? ? ? ?so maybe
>? ? ? ? ?>>? ? ? ? that's why
>? ? ? ? ?>>? ? ? ? >? ? ?it booted successfully.
>? ? ? ? ?>>? ? ? ? >? ?* I'm able to display the square wave test signal from
>? ? ? ? ?the front
>? ? ? ? ?>>? ? ? ? panel,
>? ? ? ? ?>>? ? ? ? >? ? ?though it seems to be offset vertically a bit.
>? ? ? ? ?>>? ? ? ? >
>? ? ? ? ?>>? ? ? ? > To me, this seems to tell me the battery holding the cal
>? ? ? ? ?constants
>? ? ? ? ?>>? ? ? ? is done -
>? ? ? ? ?>>? ? ? ? > going by what I know about my 54522A. It's also possible
>? ? ? ? ?some Dallas
>? ? ? ? ?>>? ? ? ? RAMs are
>? ? ? ? ?>>? ? ? ? > out of battery - though I don't know if this uses those for
>? ? ? ? ?>>? ? ? ? non-volatile
>? ? ? ? ?>>? ? ? ? > memory. I have not yet opened the units, so I've no idea
>? ? ? ? ?where the
>? ? ? ? ?>>? ? ? ? rails are,
>? ? ? ? ?>>? ? ? ? > if any caps have leaked, etc. But maybe the information
>? ? ? ? ?above gives
>? ? ? ? ?>>? ? ? ? some clues
>? ? ? ? ?>>? ? ? ? > on what's going on, enough to start thinking on it. It
>? ? ? ? ?also seems
>? ? ? ? ?>>? ? ? ? the issues
>? ? ? ? ?>>? ? ? ? > are shared very similarly, so maybe that's making the
>? ? ? ? ?repair more
>? ? ? ? ?>>? ? ? ? streamlined.
>? ? ? ? ?>>? ? ? ? > Looking forward to your input.
>? ? ? ? ?>>? ? ? ? > Thank you,
>? ? ? ? ?>>? ? ? ? > Radu.
>? ? ? ? ?>>? ? ? ? >
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>
>
>
>
>
>
>
You are seeing the tabs which are spot welded to the cell, it's not a socket, the cell is soldered to the board.? Well you might be able to pry but risk damage to the board or traces.? At this point replace the thing.? Best is to desolder it from the bottom of the board.? Definitely figure out what's up with that power supply though.
On 2/27/2025 2:32 PM, Radu Bogdan Dicher via groups.io wrote:
I lifted today the CRT card, just enough to have some access to the battery, but I'm still unsure how it's supposed to come off. I tried prying the top spring "leaf," but it seems attached (possibly soldered) to the battery - or is that a top lid over the battery? And then there's a piece of foam underneath, possibly double-sided sticking. I'd rather not remove the whole mainboard just to replace this, but I don't think I can try many more prying and pulling before?I risk something more serious due to the lack of access.
Hoping someone having done this before?recognizes the type of battery and its socket from the enclosed pictures?and has some good pointers. I am not seeing any other battery on this board - I was expecting?a bigger, cylindrical?type, but I think this must be it for the 54512B.
Thanks a bunch in advance. Radu.
On Wed, Feb 26, 2025 at 7:08?AM Radu Bogdan Dicher via groups.io <> <vondicher@...> wrote:
Thanks, Jim. I still have to perform that test where I play The Cure from my garage with the door open, which?I'm sure you'd hear from your bench!! ;))))
I tried?to pry off the battery this morning without further disassembly, but it doesn't want to come off that easily. There seems to be a blob of solder - has anyone seen that before? - on top of the holder, and some sort of?foam?tape below it. Maybe I need to apply force a little bit differently.
Unless there's some secret?regarding how to remove the battery, I'll have to at least remove at least the CRT module to gain?better access to it. I really think access to a battery - even one guaranteed?a decade - should be easier than this. So this should be possible later in the week when I have more time. Radu.
On Wed, Feb 26, 2025 at 5:38?AM Jim Ford via groups.io <> <james.ford@...> wrote:
Speaking of CR2032 coin cells, don’t spend $$ at a local store; order from Digital-Key for about $0.50 in quantity.? I usually buy 50 pieces at a time.? But then I have a keychain LED flashlight (torch for the Brits) that my kids bought me some years ago (best gift ever!) that takes 2 cells and a 3-LED baseball cap that I wear when walking my dogs at night that takes 4.? So I go through a lot of them.? Mouser might have them as well.? I’ve not ordered from D-K for a while because they buried the big product table, and it seems like something else they did got me PO’d at them.? HTH.
Jim Ford Laguna Hills, California, USA > On Feb 25, 2025, at 7:46?PM, Peter Gottlieb via groups.io <> <hpnpilot@...> wrote: > > ?CR followed by numbers indicates the physical size, CR2032 etc.? I would say if you're already in there, replace them as even if they are good they won't last much longer.? I always replace memory hold up cells in anything that crosses my bench.? Low hanging fruit. > > The power supply might be low because of an overload caused by a shorted capacitor.? Perhaps try unplugging the supply connections. I can't remember if that model's supply will run correctly without load.? But if you do go inside it, check the capacitors for capacitance, leaks and ESR. > > Peter > > >> On 2/25/2025 9:35 PM, Radu Bogdan Dicher via groups.io <> wrote: >> I've gotten a bit of a chance tonight to check a couple of things with one of the units: >> >> *Unit #2 *(S/N: 3214A00704: consecutive units!) >> >>? * Voltages on rails: >>? ? ? o +11.924V >>? ? ? o +12.050V >>? ? ? o -3.27V(fluctuating somewhat; no significant ripple on it) >>? ? ? o -5.2289V >>? ? ? o 3.5285V >>? ? ? o 5.2067V >>? * There's a coin battery on the main board, which I didn't remove yet (I'd >>? ? rather measure its voltage before I do, in case it's still good and holds >>? ? the memory). It's a Panasonic and I can only read "CR..." from it. Would >>? ? there potentially be more harm done by removing it, than simply losing the >>? ? cal constants, in case it's still good for some reason? I'm thinking of >>? ? biting the bullet and removing it, replacing it, and then seeing where >>? ? that takes me. >> >> So this second unit has more issues than just a dead battery (in case the latter checks out). I'll have to remove the power supply module and see what could be wrong with the -12V rail. I'm provisionally blaming the unruly -12V rail for the additional error this second unit has, which the first doesn't. So my money's on that the first one has a good -12V rail. >> Radu. >> >> On Tue, Feb 25, 2025 at 7:14?AM Radu Bogdan Dicher via groups.io <> <> <vondicher@...> wrote: >> >>? ? Awesome, thank you, Peter. >> >>? ? I wonder if anyone has a fresh recollection of what battery or maybe >>? ? battery-backed RAM would be suspect and possibly needed so I'd start >>? ? working on an order to have the parts ready by the time I carve out some >>? ? time to open these. From what I know about these generation scopes, >>? ? replacing the battery is probably a good idea anyway. The cal constants >>? ? seem to be gone, so nothing to lose there. >> >>? ? I wasn't able to find this information (particularly info on the battery) >>? ? in the manuals, which I find odd. >>? ? Radu. >> >> >>? ? On Tue, Feb 25, 2025 at 5:26?AM Peter Gottlieb via groups.io <> >>? ? <> <hpnpilot@...> wrote: >> >>? ? ? ? Seems like you are on the right track. Many HP scopes of that era >>? ? ? ? lose their >>? ? ? ? minds if the memory battery goes dead. >> >>? ? ? ? Peter >> >> >>? ? ? ? On 2/24/2025 11:09 PM, Radu Bogdan Dicher via groups.io <> >>? ? ? ? <> wrote: >>? ? ? ? > Hi all, >>? ? ? ? > Over the weekend I've got a couple of 54512Bs at my desk to seek to >>? ? ? ? bring back >>? ? ? ? > to full functionality. My main scope is a 54522A, and I assume they >>? ? ? ? have some >>? ? ? ? > commonalities, but I've yet to open mine (it came to me fully >>? ? ? ? refurbished and >>? ? ? ? > never needed to open the case). I'm not very familiar with this >>? ? ? ? other series, >>? ? ? ? > and hope on some good input and recommendations. >>? ? ? ? > The documentation is not as good as others I've seen from HP. >>? ? ? ? Specifically for >>? ? ? ? > this unit (54512B), Keysight only seems to have a very skinny (by HP >>? ? ? ? > standards) Service Manual which can't honestly be called >>? ? ? ? "module-level Service >>? ? ? ? > Manual," as it doesn't really into much detail on the different >>? ? ? ? modules. Then >>? ? ? ? > there's a "Front Panel Reference," which is an odd other way of >>? ? ? ? naming what I >>? ? ? ? > think is the Operating Manual. A couple other manuals have to do with >>? ? ? ? > programming. That's it. >>? ? ? ? > Sometimes in a series you have to look for the main unit, but in >>? ? ? ? this case I'm >>? ? ? ? > not sure that's the 54501A, as the catalog spec sheet seems to >>? ? ? ? suggest, or the >>? ? ? ? > 54505B, as per the SM. Maybe someone very familiar with the series >>? ? ? ? would know. >>? ? ? ? > Artek doesn't have manuals for the 54512B at all, but they do for >>? ? ? ? the 54501A, >>? ? ? ? > and if applicable, I'd get the series of six manuals they sell as a >>? ? ? ? bundle. If >>? ? ? ? > no go, I'll be a bit in a bind with fixing this given what I have at >>? ? ? ? hand. I >>? ? ? ? > am aware HP was not longer offering component SMs by this point, >>? ? ? ? though I >>? ? ? ? > don't know for a fact on this specific series and scope (but I do >>? ? ? ? regarding >>? ? ? ? > the better?/later? 54522A). >>? ? ? ? > Is this really capable of FFT to 500MHz, even if the scope is rated >>? ? ? ? to 300MHz? >>? ? ? ? > I can't make sense of that. >>? ? ? ? > Now, on to the specific issues with the units. >>? ? ? ? > *Unit #1 *(S/N: 3214A00705) >>? ? ? ? > >>? ? ? ? >? ?* Upon starting it, it reports something like "TRYING TO START >>? ? ? ? REALTIME >>? ? ? ? >? ? ?CLOCK," which is unsuccessful after a time countdown from I >>? ? ? ? think 60: >>? ? ? ? >? ? ?"REALTIME CLOCK FAILED TO START - DISABLED." >>? ? ? ? >? ?* Once I get it to display the default screen and output a trace, >>? ? ? ? it stated >>? ? ? ? >? ? ?"Default cal loaded. Re-cal instrument." >>? ? ? ? >? ?* Self Test passes all. >>? ? ? ? >? ?* I'm also seeing a solid and apparently accurate 5V from the DC >>? ? ? ? Cal output >>? ? ? ? >? ? ?in the back. I haven't tried the AC Cal output. >>? ? ? ? >? ?* Note this one had the Cal switch in the back in the UNPROTECTED >>? ? ? ? position >>? ? ? ? >? ? ?when I got it. >>? ? ? ? >? ?* I'm able to display the square wave test signal from the front >>? ? ? ? panel. >>? ? ? ? > >>? ? ? ? > *Unit #2 *(S/N: 3214A00704: consecutive units!) >>? ? ? ? > >>? ? ? ? >? ?* Upon staring it, it stated "CALIBRATION FACTOR CHECKSUM ERROR. >>? ? ? ? MOVE REAR >>? ? ? ? >? ? ?PANEL CAL SWITCH TO UNPROTECTED. POWER INSTRUMENT OFF AND THEN >>? ? ? ? ON AGAIN. >>? ? ? ? >? ? ?RE-CAL INSTRUMENT." >>? ? ? ? >? ?* It also says "Trying to start realtime clock (09290)." Maybe >>? ? ? ? that's an >>? ? ? ? >? ? ?error code? >>? ? ? ? >? ?* Upon switching the rear Cal switch to UNPROTECTED, it boots >>? ? ? ? successfully, >>? ? ? ? >? ? ?goes to a default measurement screen, but gives me a warning "Failed >>? ? ? ? >? ? ?interpolar cal." The trace seems to jump around on Y a bit. >>? ? ? ? >? ?* Self Test passes all /but/ Timebase. It also displays the same >>? ? ? ? error as >>? ? ? ? >? ? ?default screen ("Failed interpolar cal"). >>? ? ? ? >? ?* 5V out at DC Cal is good. >>? ? ? ? >? ?* This one had the Cal switch in UNPROTECTED position, so maybe >>? ? ? ? that's why >>? ? ? ? >? ? ?it booted successfully. >>? ? ? ? >? ?* I'm able to display the square wave test signal from the front >>? ? ? ? panel, >>? ? ? ? >? ? ?though it seems to be offset vertically a bit. >>? ? ? ? > >>? ? ? ? > To me, this seems to tell me the battery holding the cal constants >>? ? ? ? is done - >>? ? ? ? > going by what I know about my 54522A. It's also possible some Dallas >>? ? ? ? RAMs are >>? ? ? ? > out of battery - though I don't know if this uses those for >>? ? ? ? non-volatile >>? ? ? ? > memory. I have not yet opened the units, so I've no idea where the >>? ? ? ? rails are, >>? ? ? ? > if any caps have leaked, etc. But maybe the information above gives >>? ? ? ? some clues >>? ? ? ? > on what's going on, enough to start thinking on it. It also seems >>? ? ? ? the issues >>? ? ? ? > are shared very similarly, so maybe that's making the repair more >>? ? ? ? streamlined. >>? ? ? ? > Looking forward to your input. >>? ? ? ? > Thank you, >>? ? ? ? > Radu. >>? ? ? ? > >> >> >> >> >> >> > > > > > >
I have no personal knowledge of the this battery replacement, however my best guess would be a CR2032, or CR2025 type. The coin/button cells of this type seem to be 3V lithium. If you cannot lift the outer tang assembly vs. the inner recessed oval then it is one piece and tack welded to the battery “-“ terminal. The other side of the battery that you cannot see is held to the spring contact on the board by the spring tension of the neg assembly tang. ?You can peel the negative tang off the battery, but that generally eliminates the spring tension of the negative terminal. ?You would have to recreate that tension and install a new battery.?
This vendor has quite a few button batteries of all sizes and several with pre-mounted tangs that have been tack welded on.
Yeah, sort of permanent tabs! ?I accidentally bought 50 of the Murata tabbed CR2032s and just yanked the spot-welded tabs off with pliers. ?They will come off if you pull hard enough. ?Best to order the ones without the tabs.
On Feb 27, 2025, at 1:09?PM, Radu Bogdan Dicher via groups.io <vondicher@...> wrote:
?
Thank you, Steve.?
One other unfortunate effect?of the spot-welding of the top tab is that the battery code is not visible. I can probably destroy the battery once out, and read the CRxyzt?battery code, but would anyone have good info offhand on it? I couldn't track this info in any of the manuals.?
Or alternatively a link to the correct replacement would be even better, of course. Some years ago, I'd be confident I could source it from Keysight, but these days availability of parts seems to not quite be there anymore.?
Thanks a bunch!
Radu.?
On Thu, Feb 27, 2025 at 12:53?PM Steve Hendrix via <SteveHx=[email protected]> wrote:
On 2025-02-27 3:47 PM, Radu Bogdan Dicher via wrote:
> If I understand this right, the correct procedure is to desolder both
> tabs?... Given the top tab is spot welded, it may not be reusable? So,
> replacing?this with the appropriate coin battery socket and a new
> battery is the way to go?
When you get to the bottom side of the PCB, I'm pretty sure you'll find
three "leads" sticking thru. Two go to the top side of the cell, and one
to the underside. You'll need to carefully desolder all three to remove
the cell, then clean up the holes. Not sure if you will find a socket
that neatly fits the same footprint; you may have to just solder in the
new battery. Those tabs are a permanent part of the battery. If you find
a socket that will fit, you can just buy a standard coin cell without
the tabs of course.
To finish that thought, in terms of chemistry of type of battery, if I have more leeway in what I choose, what would be some recommendations on the chemistry of the battery?
R?zvan - thanks a bunch for those points and the PCB stuff.
Radu.
On Thu, Feb 27, 2025, 2:47 PM Radu Bogdan Dicher via <vondicher=[email protected]> wrote:
Peter,
No, but I am aware of that (though, really good point!). I assume the batteries are depleted. I also assume all they're holding is the calibration data, and the actual instrument software is saved somewhere else.
Radu.
On Thu, Feb 27, 2025, 2:28 PM Peter Brown via <peter=[email protected]> wrote:
Has anyone mentioned to watch out for grounded soldering iron tips when doing this (if the cell is not discharged or memory contents need to be kept alive using an external PSU)
Peter,
No, but I am aware of that (though, really good point!). I assume the batteries are depleted. I also assume all they're holding is the calibration data, and the actual instrument software is saved somewhere else.
Radu.
On Thu, Feb 27, 2025, 2:28 PM Peter Brown via <peter=[email protected]> wrote:
Has anyone mentioned to watch out for grounded soldering iron tips when doing this (if the cell is not discharged or memory contents need to be kept alive using an external PSU)
Has anyone mentioned to watch out for grounded soldering iron tips when doing this (if the cell is not discharged or memory contents need to be kept alive using an external PSU)
I would say that battery is a CR2430 or a BR2430 looking at the size compared the ICs around.
I replaced it also in my 8970B but there I had a holder.
I had a few days ago an issue with my E4418B that battery was empty and it has a similar solder type battery with 3 welded leads but it is a BR2/3A. I searched on different sites and manufacturers for a 3 pin compatible holder without luck. In the end I bought a small PCB adapter to CR2032 on eBay and soldered 3 female pins on the board and 3 male pins on the small PCB and plugged it in.
You can measure the battery size if you cannot read the numbers. 2032 is 20mm diameter and 3.2mm thickness.
I attached 2 photos. One is for a CR2430 battery with 3 tabs welded and one is for an adapter PCB to CR2032 that was made by someone for an 8756A SNA as a reference of what you can do.
Link for the 8756A adapter and you can download the PCB layout.
On 27/02/2025 22:09, Radu Bogdan Dicher via groups.io wrote:
Thank you, Steve. One other unfortunate effect?of the spot-welding of the top tab is that the battery code is not visible. I can probably destroy the battery once out, and read the CRxyzt?battery code, but would anyone have good info offhand on it? I couldn't track this info in any of the manuals. Or alternatively a link to the correct replacement would be even better, of course. Some years ago, I'd be confident I could source it from Keysight, but these days availability of parts seems to not quite be there anymore. Thanks a bunch! Radu.
On Thu, Feb 27, 2025 at 12:53?PM Steve Hendrix via groups.io < groups.io> <SteveHx@... <mailto:[email protected]>> wrote:
On 2025-02-27 3:47 PM, Radu Bogdan Dicher via groups.io < groups.io> wrote: > If I understand this right, the correct procedure is to desolder both > tabs?... Given the top tab is spot welded, it may not be reusable? So, > replacing?this with the appropriate coin battery socket and a new > battery is the way to go?
When you get to the bottom side of the PCB, I'm pretty sure you'll find three "leads" sticking thru. Two go to the top side of the cell, and one to the underside. You'll need to carefully desolder all three to remove the cell, then clean up the holes. Not sure if you will find a socket that neatly fits the same footprint; you may have to just solder in the new battery. Those tabs are a permanent part of the battery. If you find a socket that will fit, you can just buy a standard coin cell without the tabs of course.
Thanks, Gabor. That makes sense and I don't think it'd be so bad even in the long term. I'd personally do it in a way where this can be serviced again (in 10 years or... 25!), and a socket would provide that capability.?
In that case, I assume the exact battery would?not be such a huge concern, as long as the voltage is right (I assume 3V), and the very long duty type is being employed.?
On Thu, Feb 27, 2025 at 1:09?PM Radu Dicher <vondicher@...> wrote:
Thank you, Steve.?
One other unfortunate effect?of the spot-welding of the top tab is that the battery code is not visible. I can probably destroy the battery once out, and read the CRxyzt?battery code, but would anyone have good info offhand on it? I couldn't track this info in any of the manuals.?
Or alternatively a link to the correct replacement would be even better, of course. Some years ago, I'd be confident I could source it from Keysight, but these days availability of parts seems to not quite be there anymore.?
Thanks a bunch!
Radu.?
On Thu, Feb 27, 2025 at 12:53?PM Steve Hendrix via <SteveHx=[email protected]> wrote:
On 2025-02-27 3:47 PM, Radu Bogdan Dicher via wrote:
> If I understand this right, the correct procedure is to desolder both
> tabs?... Given the top tab is spot welded, it may not be reusable? So,
> replacing?this with the appropriate coin battery socket and a new
> battery is the way to go?
When you get to the bottom side of the PCB, I'm pretty sure you'll find
three "leads" sticking thru. Two go to the top side of the cell, and one
to the underside. You'll need to carefully desolder all three to remove
the cell, then clean up the holes. Not sure if you will find a socket
that neatly fits the same footprint; you may have to just solder in the
new battery. Those tabs are a permanent part of the battery. If you find
a socket that will fit, you can just buy a standard coin cell without
the tabs of course.
One other unfortunate effect?of the spot-welding of the top tab is that the battery code is not visible. I can probably destroy the battery once out, and read the CRxyzt?battery code, but would anyone have good info offhand on it? I couldn't track this info in any of the manuals.?
Or alternatively a link to the correct replacement would be even better, of course. Some years ago, I'd be confident I could source it from Keysight, but these days availability of parts seems to not quite be there anymore.?
On Thu, Feb 27, 2025 at 12:53?PM Steve Hendrix via <SteveHx=[email protected]> wrote:
On 2025-02-27 3:47 PM, Radu Bogdan Dicher via wrote:
> If I understand this right, the correct procedure is to desolder both
> tabs?... Given the top tab is spot welded, it may not be reusable? So,
> replacing?this with the appropriate coin battery socket and a new
> battery is the way to go?
When you get to the bottom side of the PCB, I'm pretty sure you'll find
three "leads" sticking thru. Two go to the top side of the cell, and one
to the underside. You'll need to carefully desolder all three to remove
the cell, then clean up the holes. Not sure if you will find a socket
that neatly fits the same footprint; you may have to just solder in the
new battery. Those tabs are a permanent part of the battery. If you find
a socket that will fit, you can just buy a standard coin cell without
the tabs of course.
I'm a bit ashamed to admit that in such a case, I'd probably hot glue a battery holder that I already have in place of the original and connect its leads with a pair of short wires to the pads. If done with care and the battery well has a fully molded bottom (some are basically split in two by one of the contacts) so that it can be operated safely when fixed off-board it doesn't look that bad and functions properly.
On Thu, Feb 27, 2025 at 9:48?PM Radu Bogdan Dicher via <vondicher=[email protected]> wrote:
Awesome. Thank you guys! I only did just about enough prying to figure this mustn't be the right way to remove, then asked here. It sounds like it's not a ten minute deal and needs weekend time to do.?
If I understand this right, the correct procedure is to desolder both tabs?... Given the top tab is spot welded, it may not be reusable? So, replacing?this with the appropriate coin battery socket and a new battery is the way to go?
Thanks again!
Radu.?
On Thu, Feb 27, 2025 at 12:09?PM Steve Hendrix via <SteveHx=[email protected]> wrote:
On 2025-02-27 2:32 PM, Radu Bogdan Dicher via wrote:
> I lifted today the CRT card, just enough to have some access to the
> battery, but I'm still unsure how it's supposed to come off. I tried
> prying the top spring "leaf," but it seems attached (possibly
> soldered) to the battery - or is that a top lid over the battery? And
> then there's a piece of foam underneath, possibly double-sided
> sticking. I'd rather not remove the whole mainboard just to replace
> this, but I don't think I can try many more prying and pulling
> before?I risk something more serious due to the lack of access.
Stop prying! I've used that type battery many times. The tab on top is
spot-welded to the cell, with two fingers soldered thru the PCB.
underneath is another, smaller tab, with a single finger soldered thru
the PCB. You will need to gain access to the bottom side of the PCB to
desolder that.
On 2025-02-27 3:47 PM, Radu Bogdan Dicher via groups.io wrote:
If I understand this right, the correct procedure is to desolder both tabs?... Given the top tab is spot welded, it may not be reusable? So, replacing?this with the appropriate coin battery socket and a new battery is the way to go?
When you get to the bottom side of the PCB, I'm pretty sure you'll find three "leads" sticking thru. Two go to the top side of the cell, and one to the underside. You'll need to carefully desolder all three to remove the cell, then clean up the holes. Not sure if you will find a socket that neatly fits the same footprint; you may have to just solder in the new battery. Those tabs are a permanent part of the battery. If you find a socket that will fit, you can just buy a standard coin cell without the tabs of course.
Awesome. Thank you guys! I only did just about enough prying to figure this mustn't be the right way to remove, then asked here. It sounds like it's not a ten minute deal and needs weekend time to do.?
If I understand this right, the correct procedure is to desolder both tabs?... Given the top tab is spot welded, it may not be reusable? So, replacing?this with the appropriate coin battery socket and a new battery is the way to go?
On Thu, Feb 27, 2025 at 12:09?PM Steve Hendrix via <SteveHx=[email protected]> wrote:
On 2025-02-27 2:32 PM, Radu Bogdan Dicher via wrote:
> I lifted today the CRT card, just enough to have some access to the
> battery, but I'm still unsure how it's supposed to come off. I tried
> prying the top spring "leaf," but it seems attached (possibly
> soldered) to the battery - or is that a top lid over the battery? And
> then there's a piece of foam underneath, possibly double-sided
> sticking. I'd rather not remove the whole mainboard just to replace
> this, but I don't think I can try many more prying and pulling
> before?I risk something more serious due to the lack of access.
Stop prying! I've used that type battery many times. The tab on top is
spot-welded to the cell, with two fingers soldered thru the PCB.
underneath is another, smaller tab, with a single finger soldered thru
the PCB. You will need to gain access to the bottom side of the PCB to
desolder that.
On 2025-02-27 2:32 PM, Radu Bogdan Dicher via groups.io wrote:
I lifted today the CRT card, just enough to have some access to the battery, but I'm still unsure how it's supposed to come off. I tried prying the top spring "leaf," but it seems attached (possibly soldered) to the battery - or is that a top lid over the battery? And then there's a piece of foam underneath, possibly double-sided sticking. I'd rather not remove the whole mainboard just to replace this, but I don't think I can try many more prying and pulling before?I risk something more serious due to the lack of access.
Stop prying! I've used that type battery many times. The tab on top is spot-welded to the cell, with two fingers soldered thru the PCB. underneath is another, smaller tab, with a single finger soldered thru the PCB. You will need to gain access to the bottom side of the PCB to desolder that.
Just my 2 cents worth, I think that battery is soldered in and the tags/clips are spot welded on to it. You’ll probably need to remove the board assembly to successfully remove it.
On 27 Feb 2025, at 19:36, Radu Bogdan Dicher via <vondicher@...> wrote:
One can see a lot of scratches on top of that - I think someone before?me tried replacing this with limited success.?
On Thu, Feb 27, 2025 at 11:33?AM Radu Bogdan Dicher via <vondicher=[email protected]> wrote:
I lifted today the CRT card, just enough to have some access to the battery, but I'm still unsure how it's supposed to come off. I tried prying the top spring "leaf," but it seems attached (possibly soldered) to the battery - or is that a top lid over the battery? And then there's a piece of foam underneath, possibly double-sided sticking. I'd rather not remove the whole mainboard just to replace this, but I don't think I can try many more prying and pulling before?I risk something more serious due to the lack of access.?
Hoping someone having done this before?recognizes the type of battery and its socket from the enclosed pictures?and has some good pointers. I am not seeing any other battery on this board - I was expecting?a bigger, cylindrical?type, but I think this must be it for the 54512B.?
Thanks a bunch in advance.
Radu.?
On Wed, Feb 26, 2025 at 7:08?AM Radu Bogdan Dicher via <vondicher=[email protected]> wrote:
Thanks, Jim. I still have to perform that test where I play The Cure from my garage with the door open, which?I'm sure you'd hear from your bench!! ;))))
I tried?to pry off the battery this morning without further disassembly, but it doesn't want to come off that easily. There seems to be a blob of solder - has anyone seen that before? - on top of the holder, and some sort of?foam?tape below it. Maybe I need to apply force a little bit differently.?
Unless there's some secret?regarding how to remove the battery, I'll have to at least remove at least the CRT module to gain?better access to it. I really think access to a battery - even one guaranteed?a decade - should be easier than this. So this should be possible later in the week when I have more time.?
Radu.?
On Wed, Feb 26, 2025 at 5:38?AM Jim Ford via <james.ford=[email protected]> wrote:
Speaking of CR2032 coin cells, don’t spend $$ at a local store; order from Digital-Key for about $0.50 in quantity.? I usually buy 50 pieces at a time.? But then I have a keychain LED flashlight (torch for the Brits) that my kids bought me some years ago (best gift ever!) that takes 2 cells and a 3-LED baseball cap that I wear when walking my dogs at night that takes 4.? So I go through a lot of them.? Mouser might have them as well.? I’ve not ordered from D-K for a while because they buried the big product table, and it seems like something else they did got me PO’d at them.? HTH.
Jim Ford
Laguna Hills, California, USA
> On Feb 25, 2025, at 7:46?PM, Peter Gottlieb via <hpnpilot=[email protected]> wrote:
>
> ?CR followed by numbers indicates the physical size, CR2032 etc.? I would say if you're already in there, replace them as even if they are good they won't last much longer.? I always replace memory hold up cells in anything that crosses my bench.? Low hanging fruit.
>
> The power supply might be low because of an overload caused by a shorted capacitor.? Perhaps try unplugging the supply connections. I can't remember if that model's supply will run correctly without load.? But if you do go inside it, check the capacitors for capacitance, leaks and ESR.
>
> Peter
>
>
>> On 2/25/2025 9:35 PM, Radu Bogdan Dicher via wrote:
>> I've gotten a bit of a chance tonight to check a couple of things with one of the units:
>>
>> *Unit #2 *(S/N: 3214A00704: consecutive units!)
>>
>>? * Voltages on rails:
>>? ? ? o +11.924V
>>? ? ? o +12.050V
>>? ? ? o -3.27V(fluctuating somewhat; no significant ripple on it)
>>? ? ? o -5.2289V
>>? ? ? o 3.5285V
>>? ? ? o 5.2067V
>>? * There's a coin battery on the main board, which I didn't remove yet (I'd
>>? ? rather measure its voltage before I do, in case it's still good and holds
>>? ? the memory). It's a Panasonic and I can only read "CR..." from it. Would
>>? ? there potentially be more harm done by removing it, than simply losing the
>>? ? cal constants, in case it's still good for some reason? I'm thinking of
>>? ? biting the bullet and removing it, replacing it, and then seeing where
>>? ? that takes me.
>>
>> So this second unit has more issues than just a dead battery (in case the latter checks out). I'll have to remove the power supply module and see what could be wrong with the -12V rail. I'm provisionally blaming the unruly -12V rail for the additional error this second unit has, which the first doesn't. So my money's on that the first one has a good -12V rail.
>> Radu.
>>
>> On Tue, Feb 25, 2025 at 7:14?AM Radu Bogdan Dicher via <> <vondicher=[email protected]> wrote:
>>
>>? ? Awesome, thank you, Peter.
>>
>>? ? I wonder if anyone has a fresh recollection of what battery or maybe
>>? ? battery-backed RAM would be suspect and possibly needed so I'd start
>>? ? working on an order to have the parts ready by the time I carve out some
>>? ? time to open these. From what I know about these generation scopes,
>>? ? replacing the battery is probably a good idea anyway. The cal constants
>>? ? seem to be gone, so nothing to lose there.
>>
>>? ? I wasn't able to find this information (particularly info on the battery)
>>? ? in the manuals, which I find odd.
>>? ? Radu.
>>
>>
>>? ? On Tue, Feb 25, 2025 at 5:26?AM Peter Gottlieb via
>>? ? <> <hpnpilot=[email protected]> wrote:
>>
>>? ? ? ? Seems like you are on the right track.? Many HP scopes of that era
>>? ? ? ? lose their
>>? ? ? ? minds if the memory battery goes dead.
>>
>>? ? ? ? Peter
>>
>>
>>? ? ? ? On 2/24/2025 11:09 PM, Radu Bogdan Dicher via
>>? ? ? ? <> wrote:
>>? ? ? ? > Hi all,
>>? ? ? ? > Over the weekend I've got a couple of 54512Bs at my desk to seek to
>>? ? ? ? bring back
>>? ? ? ? > to full functionality. My main scope is a 54522A, and I assume they
>>? ? ? ? have some
>>? ? ? ? > commonalities, but I've yet to open mine (it came to me fully
>>? ? ? ? refurbished and
>>? ? ? ? > never needed to open the case). I'm not very familiar with this
>>? ? ? ? other series,
>>? ? ? ? > and hope on some good input and recommendations.
>>? ? ? ? > The documentation is not as good as others I've seen from HP.
>>? ? ? ? Specifically for
>>? ? ? ? > this unit (54512B), Keysight only seems to have a very skinny (by HP
>>? ? ? ? > standards) Service Manual which can't honestly be called
>>? ? ? ? "module-level Service
>>? ? ? ? > Manual," as it doesn't really into much detail on the different
>>? ? ? ? modules. Then
>>? ? ? ? > there's a "Front Panel Reference," which is an odd other way of
>>? ? ? ? naming what I
>>? ? ? ? > think is the Operating Manual. A couple other manuals have to do with
>>? ? ? ? > programming. That's it.
>>? ? ? ? > Sometimes in a series you have to look for the main unit, but in
>>? ? ? ? this case I'm
>>? ? ? ? > not sure that's the 54501A, as the catalog spec sheet seems to
>>? ? ? ? suggest, or the
>>? ? ? ? > 54505B, as per the SM. Maybe someone very familiar with the series
>>? ? ? ? would know.
>>? ? ? ? > Artek doesn't have manuals for the 54512B at all, but they do for
>>? ? ? ? the 54501A,
>>? ? ? ? > and if applicable, I'd get the series of six manuals they sell as a
>>? ? ? ? bundle. If
>>? ? ? ? > no go, I'll be a bit in a bind with fixing this given what I have at
>>? ? ? ? hand. I
>>? ? ? ? > am aware HP was not longer offering component SMs by this point,
>>? ? ? ? though I
>>? ? ? ? > don't know for a fact on this specific series and scope (but I do
>>? ? ? ? regarding
>>? ? ? ? > the better?/later? 54522A).
>>? ? ? ? > Is this really capable of FFT to 500MHz, even if the scope is rated
>>? ? ? ? to 300MHz?
>>? ? ? ? > I can't make sense of that.
>>? ? ? ? > Now, on to the specific issues with the units.
>>? ? ? ? > *Unit #1 *(S/N: 3214A00705)
>>? ? ? ? >
>>? ? ? ? >? ?* Upon starting it, it reports something like "TRYING TO START
>>? ? ? ? REALTIME
>>? ? ? ? >? ? ?CLOCK," which is unsuccessful after a time countdown from I
>>? ? ? ? think 60:
>>? ? ? ? >? ? ?"REALTIME CLOCK FAILED TO START - DISABLED."
>>? ? ? ? >? ?* Once I get it to display the default screen and output a trace,
>>? ? ? ? it stated
>>? ? ? ? >? ? ?"Default cal loaded. Re-cal instrument."
>>? ? ? ? >? ?* Self Test passes all.
>>? ? ? ? >? ?* I'm also seeing a solid and apparently accurate 5V from the DC
>>? ? ? ? Cal output
>>? ? ? ? >? ? ?in the back. I haven't tried the AC Cal output.
>>? ? ? ? >? ?* Note this one had the Cal switch in the back in the UNPROTECTED
>>? ? ? ? position
>>? ? ? ? >? ? ?when I got it.
>>? ? ? ? >? ?* I'm able to display the square wave test signal from the front
>>? ? ? ? panel.
>>? ? ? ? >
>>? ? ? ? > *Unit #2 *(S/N: 3214A00704: consecutive units!)
>>? ? ? ? >
>>? ? ? ? >? ?* Upon staring it, it stated "CALIBRATION FACTOR CHECKSUM ERROR.
>>? ? ? ? MOVE REAR
>>? ? ? ? >? ? ?PANEL CAL SWITCH TO UNPROTECTED. POWER INSTRUMENT OFF AND THEN
>>? ? ? ? ON AGAIN.
>>? ? ? ? >? ? ?RE-CAL INSTRUMENT."
>>? ? ? ? >? ?* It also says "Trying to start realtime clock (09290)." Maybe
>>? ? ? ? that's an
>>? ? ? ? >? ? ?error code?
>>? ? ? ? >? ?* Upon switching the rear Cal switch to UNPROTECTED, it boots
>>? ? ? ? successfully,
>>? ? ? ? >? ? ?goes to a default measurement screen, but gives me a warning "Failed
>>? ? ? ? >? ? ?interpolar cal." The trace seems to jump around on Y a bit.
>>? ? ? ? >? ?* Self Test passes all /but/ Timebase. It also displays the same
>>? ? ? ? error as
>>? ? ? ? >? ? ?default screen ("Failed interpolar cal").
>>? ? ? ? >? ?* 5V out at DC Cal is good.
>>? ? ? ? >? ?* This one had the Cal switch in UNPROTECTED position, so maybe
>>? ? ? ? that's why
>>? ? ? ? >? ? ?it booted successfully.
>>? ? ? ? >? ?* I'm able to display the square wave test signal from the front
>>? ? ? ? panel,
>>? ? ? ? >? ? ?though it seems to be offset vertically a bit.
>>? ? ? ? >
>>? ? ? ? > To me, this seems to tell me the battery holding the cal constants
>>? ? ? ? is done -
>>? ? ? ? > going by what I know about my 54522A. It's also possible some Dallas
>>? ? ? ? RAMs are
>>? ? ? ? > out of battery - though I don't know if this uses those for
>>? ? ? ? non-volatile
>>? ? ? ? > memory. I have not yet opened the units, so I've no idea where the
>>? ? ? ? rails are,
>>? ? ? ? > if any caps have leaked, etc. But maybe the information above gives
>>? ? ? ? some clues
>>? ? ? ? > on what's going on, enough to start thinking on it. It also seems
>>? ? ? ? the issues
>>? ? ? ? > are shared very similarly, so maybe that's making the repair more
>>? ? ? ? streamlined.
>>? ? ? ? > Looking forward to your input.
>>? ? ? ? > Thank you,
>>? ? ? ? > Radu.
>>? ? ? ? >
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