Re: Pozidrive screws on HP covers
On Sat, Sep 17, 2022 at 11:33 PM, vk2bea wrote:
Pozidrive and not Philips.
That'd be Pozidriv and Phillips, not Pozidrive and Philips. Using a Phillips screwdriver on a Pozidriv screw causes excessive wear to the screwhead. Brands like HP/Agilent/Keysight and Tektronix almost exclusively use(d) Pozidriv screws. Raymond
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Re: Pozidrive screws on HP covers
Phillips head screws are used only in the United States and are poor indeed. Elsewhere, except in Japan, crosshead screws are PoziDriv.
Japanese cross head screws are most likely JIS, quite similar to PoziDriv. Using a Phillips driver in these screw will damage them.
Lots of PoziDriv screwdrivers are available on Amazon. You want sizes 1, 2 and 3.
If you ever work on Japanese electronics, you need a set of JIS drivers also.
Larry Sent via the Samsung Galaxy S10
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-------- Original message -------- From: Radu Bogdan Dicher <vondicher@...> Date: 9/17/22 2:40 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Pozidrive screws on HP covers
Interesting. Maybe that's why I've had such a hard time trying to avoid ruining those as frequently as I had.? Do you have an image with a "pozidrive" tip? Radu.?
I failed to realize, until recently, that the screws on the covers on many HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was only after I actually used a Pozidrive on one that I felt how much better it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again!
 ??
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Re: Pozidrive screws on HP covers
Easy to find Pozi drive tools on ebay or at many specialty stores. I have and commonly use Pozi 0,1,2 drivers. It makes a REAL difference.
Cheers!
Bruce
Quoting Radu Bogdan Dicher <vondicher@...>:
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Interesting. Maybe that's why I've had such a hard time trying to avoid
ruining those as frequently as I had.
Do you have an image with a "pozidrive" tip?
Radu.
On Sat, Sep 17, 2022, 2:33 PM vk2bea via groups.io <vk2bea=
[email protected]> wrote:
I failed to realize, until recently, that the screws on the covers on many
HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was
only after I actually used a Pozidrive on one that I felt how much better
it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again!
|
Re: Pozidrive screws on HP covers
Interesting. Maybe that's why I've had such a hard time trying to avoid ruining those as frequently as I had.? Do you have an image with a "pozidrive" tip? Radu.?
I failed to realize, until recently, that the screws on the covers on many HP instruments are Pozidrive and not Philips.
Had I looked more carefully I would have seen the X indicator but it was only after I actually used a Pozidrive on one that I felt how much better it was! Not surprisingly it's a much better / firmer fit.
Live and learn I guess. I'll never use a Philips on one again!
 ??
|
Pozidrive screws on HP covers
I failed to realize, until recently, that the screws on the covers on many HP instruments are Pozidrive and not Philips. Had I looked more carefully I would have seen the X indicator but it was only after I actually used a Pozidrive on one that I felt how much better it was! Not surprisingly it's a much better / firmer fit. Live and learn I guess. I'll never use a Philips on one again!  ??
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I got them all but, Radu, you really should edit photos for image size before sending them as Group emails. Remember that email attachments incur about 30% overhead! Each email was 21 MB big. There are lots of free image editors around...
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
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On 9/17/2022 2:19 PM, Radu Bogdan Dicher wrote: Apologies if my attachments have been too large for some inboxes. Could anyone please confirm the message was received by at least some people and by the forum?
Thank?you,
Radu.
On Sat, Sep 17, 2022, 2:09 PM Radu Bogdan Dicher via groups.io <> <vondicher@... <mailto:[email protected]>> wrote:
By "top PCB" I mean the one on the right side as one faces the rear
of the unit (A15), and "bottom PCB" the left side one (which is also
the one with the large PS caps) - A14.
Radu.
On Sat, Sep 17, 2022 at 1:59 PM Radu Bogdan Dicher via groups.io
<> <vondicher@...
<mailto:[email protected]>> wrote:
Still working on the PS disassembly procedure.
I removed two screws at the back:
image.png
And the top PCB started wiggling a bit, though it is still is
attached with two inaccessible screws:
image.png
As these are facing the row of shielded modules that goes from
front to back of unit.
image.png
I surely hope I don't have to hollow the entire unit just to get
the PS out?...
If I try from the other side, the side panel is also obstructing
access to a couple of screws:
image.png
The same screws seen from the inside of the unit:
image.png
The bottom PCB seems to be used as a card into a header:
image.png
So I assume this one may detach a little easier, though the caps
are placed in their own sleeves. Are those sleeves just sliding out?
Thank you for your insights!
Radu.
On Sat, Sep 17, 2022 at 1:43 PM Radu Dicher <vondicher@...
<mailto:vondicher@...>> wrote:
Well, further schematic errors... (thanks a ton to Ozan who
straightened me on this one). C2 and C4, as they "stand" on
the schematic, are opposite in polarity. The schematic is
incorrect:
image.png
C2 should be reversed from what the schematic says (positive
on bottom).
Hope this helps someone down the line.
Radu.
On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via
groups.io <>
<patricio_greco@... <mailto:[email protected]>>
wrote:
I’m sorry I’ve a little mixed the capacitor reference
numbers . You have >= 20v on C100 / 200 ? This is the
start. I had similar problems with my power supply. So I
decided to remove it and test the components one by one.
I recommend this procedure because it’s dangerous to
have the rest of instrument conected to a faulty power
supply. There are 30% less now but can go up , no much
because it’s has a great design but in my view keeps
being uncomfortable .
Is not difficult to remove the complete module .
Regards
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento Aeronáutico de la Defensa
OMAD-001
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557 <tel:+5411-4455-2557>
F: +5411-4032-0072 <tel:+5411-4032-0072>
www.servicios-electronicos.com
<>
On 17 Sep 2022, at 15:21, Radu Bogdan Dicher
<vondicher@... <mailto:vondicher@...>> wrote:
?
To prevent any confusion, when I said I am reading 40V
instead of 55V, this is between the negative legs of
C2 and C4. Not at either one's legs vs ground, or over
either one.
This replicates step 2 from Service Group 8 (p.8-F-1).
There was no way to connect to what they're calling
for ("the junction of R1 and CR2 and R2 and CR4").
Hopefully this helps with the clarity of my empirical
data.
Radu.
On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher
via groups.io <>
<vondicher@...
<mailto:[email protected]>> wrote:
Hi Patricio,
One overall conclusion is that all rails are down
by about 30% (mind you, the same rate). Given
they're all referenced to the +15V rail, the
running assumption is that something's wrong with
the?+15V regulator.
I see less than 1.8V over C2.
Radu.
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco
via groups.io <>
<patricio_greco@...
<mailto:[email protected]>> wrote:
Please note that the voltage outputs are : + -
15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40
Vdc is ok. Please take a look to power supply
schematic …
image0.jpeg
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento Aeronáutico de
la Defensa OMAD-001
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557 <tel:+5411-4455-2557>
F: +5411-4032-0072 <tel:+5411-4032-0072>
www.servicios-electronicos.com
<>
On 17 Sep 2022, at 12:39, Radu Bogdan Dicher
<vondicher@...
<mailto:vondicher@...>> wrote:
?
I whipped out my longest probes - an inspired
overstock purchase from maybe Anchor near
SF?... - (pictures added to album, hoping
they give some ideas to others get that deep
inside the belly of this unit) - and I am
getting 40V at the minus leg of C2 and C4 (my
probing points), vs. an expected 55V.
Interestingly, as soon as I power off the
unit, the voltage there jumps up to about
45V, and even raises a bit more as the unit
is standing powered off (5 minutes later I
measure about 47V...).
Continuing my investigation.
Radu.
On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan
Dicher via groups.io <>
<vondicher@...
<mailto:[email protected]>> wrote:
Thank you all for sharing your thoughts.
I tried sending some pictures yesterday
by replying to the email chain with
attachments, but in doing so I exceeded
the max size. I created a photo
album?instead:
/g/HP-Agilent-Keysight-equipment/album?id=278590
</g/HP-Agilent-Keysight-equipment/album?id=278590>.
Will keep investigating this morning. I'm
surprised?to not find some paragraphs on
removing (each) modules in their
troubleshooting sections (typically with
images), which I expect from an HP manual
(particularly component-level). Anyway,
that concludes my whining and will go
ahead and dig in there more vigorously.
Radu.
On Sat, Sep 17, 2022 at 5:25 AM Patricio
A. Greco via groups.io <>
<patricio_greco@...
<mailto:[email protected]>> wrote:
I have a HP3335A. I started to
experiment problems as cpu freeze and
leveling errors and I found
microscopic cracks on power supply
board also I removed the transistors
and found an anormal slope on
characteristic curves (this is
thermal deterioration). Replaced the
transistors and re-soldered the
complete board, Also I removed the
capacitors for test , these was ok .
Cleaned the contacts and mounted
again. After that work, instrument
started to work like never. It??s
very very flat, let me show you the
results. I attached the response
curves I measured. X Avis is
logarithmic starting @1 MHz , and Y
Axis is in dB relative to 1 MHz. I
used 3 different methods to measure.
Regards,
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de
Mantenimiento?Aeronáutico de la
Defensa OMAD-001
Laboratorio de Calibración ISO
17025?AREA: RF/MW
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
www.servicios-electronicos.com.ar
<>
On 17 Sep 2022, at 08:01, Harold
Foster <halfoster@...
<mailto:halfoster@...>> wrote:
Taking the assemblies loose is
almost essential to troubleshooting
the supply boards, but *very
important:* You have to install a
jumper to reconnect the ground - the
boards are grounded through one of
the brackets (the one to the bottom
of the chassis if I remember
correctly) and will be disconnected
when it it taken loose.
Hal WhatsApp Image 2022-07-21 at 3.19.42
PM.jpeg
|
Hello All, I recently acquired a HP 8340B. Unfortunately it's not fully functional. There is a problem when it crosses bands 3 and 4. But before going in the troubleshooting, I noticed that an internal cover is missing, see attached picture. As there is a warning saying "do not operate for an extended periods without this cover to ensure proper cooling", I would like to reinstall it. Does anyone of you would have one to sell or knows where I could buy one? I also noticed that one screw is missing for the external bottom cover. I think this is a typical screw for HP instruments covers, not specific for the 8340B. If someone has one to sell, I would appreciate it.  
|
On Sat, Sep 17, 2022 at 11:17 PM, Raymond Domp Frank wrote:
ISTR that the complete large extruded card cage can easily be removed by loosening the SMA's and a few screws, fixing it to the chassis.
Thinking a bit more; I remember 4 screws, easily reached from the top of the extruded block, if I'm not mistaken. Raymond
|
Apologies if my attachments have been too large for some inboxes. Could anyone please confirm the message was received by at least some people and by the forum? Thank?you, Radu.?
On Sat, Sep 17, 2022, 2:09 PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: By "top PCB" I mean the one on the right side as one faces the rear of the unit (A15), and "bottom PCB" the left side one (which is also the one with the large PS caps) - A14.? Radu.?
On Sat, Sep 17, 2022 at 1:59 PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Still working on the PS disassembly procedure.? I removed two screws at the back: And the top PCB started wiggling a bit, though it is still is attached with two inaccessible screws: As these are facing the row of shielded modules that goes from front to back of unit.? I surely hope I don't have to hollow the entire unit just to get the PS out?...? If I try from the other side, the side panel is also obstructing access to a couple of screws: The same screws seen from the inside of the unit: The bottom PCB seems to be used as a card into a header: So I assume this one may detach a little easier, though the caps are placed in their own sleeves. Are those sleeves just sliding out? Thank you for your insights! Radu.?
On Sat, Sep 17, 2022 at 1:43 PM Radu Dicher < vondicher@...> wrote: Well, further schematic errors... (thanks a ton to Ozan who straightened me on this one). C2 and C4, as they "stand" on the schematic, are opposite in polarity. The schematic is incorrect: C2 should be reversed from what the schematic says (positive on bottom). Hope this helps someone down the line.? Radu.?
On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I’m sorry I’ve a little mixed the capacitor reference numbers . You have >= 20v on C100 / 200 ? This is the start. I had similar problems with my power supply. So I decided to remove it and test the components one by one. I recommend this procedure because it’s dangerous to have the rest of instrument conected to a faulty power supply. There are 30% less now but can go up , no much because it’s has a great design but in my view keeps being uncomfortable .?
Is not difficult to remove the complete module .?
Regards? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 15:21, Radu Bogdan Dicher <vondicher@...> wrote:
? To prevent any confusion, when I said I am reading 40V instead of 55V, this is between the negative legs of C2 and C4. Not at either one's legs vs ground, or over either one.? This replicates step 2 from Service Group 8 (p.8-F-1). There was no way to connect to what they're calling for ("the junction of R1 and CR2 and R2 and CR4").? Hopefully this helps with the clarity of my empirical data.? Radu.?? On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
On Sat, Sep 17, 2022 at 10:58 PM, Radu Bogdan Dicher wrote:
Still working on the PS disassembly procedure.
ISTR that the complete large extruded card cage can easily be removed by loosening the SMA's and a few screws, fixing it to the chassis. Maybe that's an option, instead of taking the PSU apart and removing it, which seems to be? a PITA, from what I read. Raymond
|
By "top PCB" I mean the one on the right side as one faces the rear of the unit (A15), and "bottom PCB" the left side one (which is also the one with the large PS caps) - A14.? Radu.?
On Sat, Sep 17, 2022 at 1:59 PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Still working on the PS disassembly procedure.? I removed two screws at the back: And the top PCB started wiggling a bit, though it is still is attached with two inaccessible screws: As these are facing the row of shielded modules that goes from front to back of unit.? I surely hope I don't have to hollow the entire unit just to get the PS out?...? If I try from the other side, the side panel is also obstructing access to a couple of screws: The same screws seen from the inside of the unit: The bottom PCB seems to be used as a card into a header: So I assume this one may detach a little easier, though the caps are placed in their own sleeves. Are those sleeves just sliding out? Thank you for your insights! Radu.?
On Sat, Sep 17, 2022 at 1:43 PM Radu Dicher < vondicher@...> wrote: Well, further schematic errors... (thanks a ton to Ozan who straightened me on this one). C2 and C4, as they "stand" on the schematic, are opposite in polarity. The schematic is incorrect: C2 should be reversed from what the schematic says (positive on bottom). Hope this helps someone down the line.? Radu.?
On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I’m sorry I’ve a little mixed the capacitor reference numbers . You have >= 20v on C100 / 200 ? This is the start. I had similar problems with my power supply. So I decided to remove it and test the components one by one. I recommend this procedure because it’s dangerous to have the rest of instrument conected to a faulty power supply. There are 30% less now but can go up , no much because it’s has a great design but in my view keeps being uncomfortable .?
Is not difficult to remove the complete module .?
Regards? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 15:21, Radu Bogdan Dicher <vondicher@...> wrote:
? To prevent any confusion, when I said I am reading 40V instead of 55V, this is between the negative legs of C2 and C4. Not at either one's legs vs ground, or over either one.? This replicates step 2 from Service Group 8 (p.8-F-1). There was no way to connect to what they're calling for ("the junction of R1 and CR2 and R2 and CR4").? Hopefully this helps with the clarity of my empirical data.? Radu.?? On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
Still working on the PS disassembly procedure.? I removed two screws at the back: And the top PCB started wiggling a bit, though it is still is attached with two inaccessible screws: As these are facing the row of shielded modules that goes from front to back of unit.? I surely hope I don't have to hollow the entire unit just to get the PS out?...? If I try from the other side, the side panel is also obstructing access to a couple of screws: The same screws seen from the inside of the unit: The bottom PCB seems to be used as a card into a header: So I assume this one may detach a little easier, though the caps are placed in their own sleeves. Are those sleeves just sliding out? Thank you for your insights! Radu.?
On Sat, Sep 17, 2022 at 1:43 PM Radu Dicher < vondicher@...> wrote: Well, further schematic errors... (thanks a ton to Ozan who straightened me on this one). C2 and C4, as they "stand" on the schematic, are opposite in polarity. The schematic is incorrect: C2 should be reversed from what the schematic says (positive on bottom). Hope this helps someone down the line.? Radu.?
On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I’m sorry I’ve a little mixed the capacitor reference numbers . You have >= 20v on C100 / 200 ? This is the start. I had similar problems with my power supply. So I decided to remove it and test the components one by one. I recommend this procedure because it’s dangerous to have the rest of instrument conected to a faulty power supply. There are 30% less now but can go up , no much because it’s has a great design but in my view keeps being uncomfortable .?
Is not difficult to remove the complete module .?
Regards? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 15:21, Radu Bogdan Dicher <vondicher@...> wrote:
? To prevent any confusion, when I said I am reading 40V instead of 55V, this is between the negative legs of C2 and C4. Not at either one's legs vs ground, or over either one.? This replicates step 2 from Service Group 8 (p.8-F-1). There was no way to connect to what they're calling for ("the junction of R1 and CR2 and R2 and CR4").? Hopefully this helps with the clarity of my empirical data.? Radu.?? On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
Well, further schematic errors... (thanks a ton to Ozan who straightened me on this one). C2 and C4, as they "stand" on the schematic, are opposite in polarity. The schematic is incorrect: C2 should be reversed from what the schematic says (positive on bottom). Hope this helps someone down the line.? Radu.?
On Sat, Sep 17, 2022 at 12:03 PM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I’m sorry I’ve a little mixed the capacitor reference numbers . You have >= 20v on C100 / 200 ? This is the start. I had similar problems with my power supply. So I decided to remove it and test the components one by one. I recommend this procedure because it’s dangerous to have the rest of instrument conected to a faulty power supply. There are 30% less now but can go up , no much because it’s has a great design but in my view keeps being uncomfortable .?
Is not difficult to remove the complete module .?
Regards? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 15:21, Radu Bogdan Dicher <vondicher@...> wrote:
? To prevent any confusion, when I said I am reading 40V instead of 55V, this is between the negative legs of C2 and C4. Not at either one's legs vs ground, or over either one.? This replicates step 2 from Service Group 8 (p.8-F-1). There was no way to connect to what they're calling for ("the junction of R1 and CR2 and R2 and CR4").? Hopefully this helps with the clarity of my empirical data.? Radu.?? On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
On 9/17/22 11:27 AM, walter shawlee wrote:
There is a huge assortment of HP spare parts there, let me know if you need something not shown, as I have thousands of HP parts we are trying to clear out.
I see HP LED displays on your page, but not what I'm looking for.? I'll bet that you do not have 1990-0335 nor 5082-7405 (-7415 will do in a pinch) nor 5082-7466 (looks same, different pinout?, also in a pinch) -- Jeff Woolsey {{woolsey,jlw}@jlw,first.last@{gmail,jlw}}.com Nature abhors straight antennas, clean lenses, and empty storage. "Delete! Delete! OK!" -Dr. Bronner on disk space management Card-sorting, Joel. -Crow on solitaire
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I’m sorry I’ve a little mixed the capacitor reference numbers . You have >= 20v on C100 / 200 ? This is the start. I had similar problems with my power supply. So I decided to remove it and test the components one by one. I recommend this procedure because it’s dangerous to have the rest of instrument conected to a faulty power supply. There are 30% less now but can go up , no much because it’s has a great design but in my view keeps being uncomfortable .?
Is not difficult to remove the complete module .?
Regards? Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072
toggle quoted message
Show quoted text
On 17 Sep 2022, at 15:21, Radu Bogdan Dicher <vondicher@...> wrote:
? To prevent any confusion, when I said I am reading 40V instead of 55V, this is between the negative legs of C2 and C4. Not at either one's legs vs ground, or over either one.? This replicates step 2 from Service Group 8 (p.8-F-1). There was no way to connect to what they're calling for ("the junction of R1 and CR2 and R2 and CR4").? Hopefully this helps with the clarity of my empirical data.? Radu.?? On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
?
Lots of tek and hp goodies added to the stuff page, reduced the price on the Tek AA501A distortion analyzer package, added a nice HP power meter (436A) and sensor, and many $1 and R+D items added.
There is a huge assortment of HP spare parts there, let me know if you need something not shown, as I have thousands of HP parts we are trying to clear out. Have lots of REAR feet for hp instruments if anybody can use them, free. these go on large generators, counters, etc. Also have a lot of paper hp manuals, if you will be up this way, you are welcome to stop in and look for any you can use. not ideal for shipping, just too much weight.
?
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.
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To prevent any confusion, when I said I am reading 40V instead of 55V, this is between the negative legs of C2 and C4. Not at either one's legs vs ground, or over either one.? This replicates step 2 from Service Group 8 (p.8-F-1). There was no way to connect to what they're calling for ("the junction of R1 and CR2 and R2 and CR4").? Hopefully this helps with the clarity of my empirical data.? Radu.??
On Sat, Sep 17, 2022 at 11:13 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
Hi Patricio, One overall conclusion is that all rails are down by about 30% (mind you, the same rate). Given they're all referenced to the +15V rail, the running assumption is that something's wrong with the?+15V regulator. I see less than 1.8V over C2. Radu.??
On Sat, Sep 17, 2022 at 10:15 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072 On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
Re: HP 400E sticky needle
Ok further discovery. It is peeling and that was getting in the way of the needle. Just couldn’t see it. I’ve tried the preemptive fix of applying a bit of pritt stick melted in boiling water to the edge. Used this before on gelatin legends. This sticks the flakes down with minimal risk. Fingers crossed.?
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Please note that the voltage outputs are : + - 15 vdc , 5 vdc and -5.2 Vdc … If C2 has > 40 Vdc is ok. Please take a look to power supply schematic …
 Ing. Patricio A. GrecoTaller Aeronáutico de Reparación 1B-349Organización de Mantenimiento Aeronáutico de la Defensa OMAD-001Gral. Martín Rodríguez 2159San Miguel (1663)Buenos AiresT:?+5411-4455-2557F:?+5411-4032-0072
toggle quoted message
Show quoted text
On 17 Sep 2022, at 12:39, Radu Bogdan Dicher <vondicher@...> wrote:
? I whipped out my longest probes - an inspired overstock purchase from maybe Anchor near SF?... - (pictures added to album, hoping they give some ideas to others get that deep inside the belly of this unit) - and I am getting 40V at the minus leg of C2 and C4 (my probing points), vs. an expected 55V. Interestingly, as soon as I power off the unit, the voltage there jumps up to about 45V, and even raises a bit more as the unit is standing powered off (5 minutes later I measure about 47V...).
Continuing my investigation.? Radu.? On Sat, Sep 17, 2022 at 6:01 AM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: Thank you all for sharing your thoughts.?
Will keep investigating this morning. I'm surprised?to not find some paragraphs on removing (each) modules in their troubleshooting sections (typically with images), which I expect from an HP manual (particularly component-level). Anyway, that concludes my whining and will go ahead and dig in there more vigorously.? Radu.?
On Sat, Sep 17, 2022 at 5:25 AM Patricio A. Greco via <patricio_greco= [email protected]> wrote: I have a HP3335A. I started to experiment problems as cpu freeze and leveling errors and I found microscopic cracks on power supply board also I removed the transistors and found an anormal slope on characteristic curves (this is thermal deterioration). Replaced the transistors and re-soldered the complete board, Also I removed the capacitors for test , these was ok . Cleaned the contacts and mounted again. After that work, instrument started to work like never. It??s very very flat, let me show you the results. I attached the response curves I measured. X Avis is logarithmic starting @1 MHz , and Y Axis is in dB relative to 1 MHz. I used 3 different methods to measure.?
Regards,?
Ing. Patricio A. Greco
Taller Aeronáutico de Reparación 1B-349
Organización de Mantenimiento?Aeronáutico de la Defensa OMAD-001
Laboratorio de Calibración ISO 17025?AREA: RF/MW?
Gral. Martín Rodríguez 2159
San Miguel (1663)
Buenos Aires
T: +5411-4455-2557
F: +5411-4032-0072
Taking the assemblies loose is almost essential to troubleshooting the supply boards, but very important: You have to install a jumper to reconnect the ground - the boards are grounded through one of the brackets (the one to the bottom of the chassis if I remember correctly) and will be disconnected when it it taken loose.
Hal
|
vk2bea
Patricio A. Greco