Re: HP8510C TRL Calibration
Hi , you can visit the scikit-rf? In the past, I tried some features of this software tools, but I did not go beyond a simple plot of graphs. I remember that you can define a virtual VNA, and perform a calibration starting from the measurements of the devices of a cal kit, and then apply the calibration to the raw measurements of the device under test . Good documentation and examples, Python language Regards? Maurizio IZ1MDJ ?
Networks
The central object in?skrf?is a N-port microwave??object. A??can be created in a number of ways, one way is from data stored in a touchstone file"
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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?
?
many thanks, N ?
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HP3325A Trouble, Calibration FAIL 2 & 3
Hi,
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?
?
Ralf
?
?
?
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Re: HP 54512B (pair) repair
I modified my soldering station lije this:
?
Instead using the hard ground wire to the tip I replaced it with a 1 MOhm resistor inside the soldering station.
?
No more risk of shorting stuff, and still a 0V potential in the tip.
?
Works for me.
?
Leo
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Re: HP 54512B (pair) repair
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.
Wilko
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Re: Adding Display Backlights
That looks awesome!
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Show quoted text
On 2/27/2025 8:59 AM, Jared Cabot via groups.io wrote: You could always do an OLED conversion..
I have made a few and they look fantastic.
Won't help with the LCR meter, but should be very compatuble with the PSU.
Jared
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Re: HP 54512B (pair) repair
Peter, 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.? Radu.?
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.
>? ? ? ? ?>>? ? ? ? >
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>? ? ? ? ?>
>
>
>
>
>
>
>
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Re: HP 54512B (pair) repair
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
toggle quoted message
Show quoted text
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.
>>? ? ? ? >
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Re: HP 54512B (pair) repair
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. | |
Ralf Rosche
