Agilent E3631A issue - display shows limit values, no errors but no output (0,0)

[free_electron]

every other symbol on that page has power pins.... just not that one...  that one is referred on the processor page... in a table. very weird...


i've found mistakes in other schematics too... E3610 schematics show mosfets as power stages. some versions show 4 ... there's 2 and they are darlingtons... Biassed darlingtons on top of that ! i could understand if they shown two fets and two darlingtons to permutate between the 3610/3611 and the 3612 (that one uses irf440 fets. also a rare beast.) but no.. 4 fets two each with same ref des.

[IanJ]

Hi Ian,
searching in your videos I found two (part 1 part 2) about this PSU E3631A. A few days ago I searched on YT but I haven't seen your videos.

Unfortunately my understanding of spoken English is not very good and therefore I have not understood much of your speech (maybe putting some subtitles, even in English, can be useful).
Anyway the guilty area is always the same. I have reference voltage +/- 10V...something get out from DAC (pin 3 of U13), probably U9 and U10 are suspected as Electron Wrangler suggested.

I just had a quick look at my own repair video(s) on the E3631A and note that most if not all of the problems on my unit were open circuit resistors, specifically just about all the GREEN coloured resistors. So, before changing out any IC's I would go over those resistors and make sure they are ok.

Ian.

[Spectrum]

Dear Wrangler  , I repaired another E36xx series 4 years ago (3632 if I'm not wrong, 15V7A or 30V4A 120W) and in the desk I think have some OP27 and AD706, so I can replace all. I just ordered 4 TL074C and 2 4051, probably next week will arrive the package. I think it is better to desolder the 220nF capacitors near U9 and U10, to have more space and work more accurately.

All true what you say, in fact these PSUs are famous for this, however they are very beautiful, expensive (even used) and although I would never spend the money they cost, when I find a used one for about 90/100 euros, I can not resist and buy it.

All the rest is lipstick, glitter and hats.

here we say A lot of smoke and little roast 

Ciao and good night

[Spectrum]

Hi Ian, yes I know. if you read at the beginning I have checked these green resistors, also out of circuit to be more certain (R4 and R5, R5 is 31,5 Kohm, datasheet 30K 0,1%  )

[free_electron]

most if not all of the problems on my unit were open circuit resistors, specifically just about all the GREEN coloured resistors. So, before changing out any IC's I would go over those resistors and make sure they are ok.

the electrodes on those things dissolve over time ... i've seen that happen too. but only on supplies that were in relatively damp areas.

[Spectrum]

Hi, finally I have the necessary ICs. Replaced U4, U7, U9, U10 U13 but nothing has changed....

[ThaiGuy]

HI Spectrum,
Would you mind sharing the schematics?
THanks

[ThaiGuy]

Hi Spectrum,
Would you mind sharing the schematics?
Thanks

[alm]

Just find an older version of the service manual before Agilent removed the schematics. For me, the second and third Google result for e3631a service manual were:
https://engineering.case.edu/lab/circuitslab/sites/engineering.case.edu.lab.circuitslab/files/docs/Agilent_E3631_Power_Supply_Service_Guide.pdf
https://dev.xdevs.com/attachments/146

Both contain the exact same file that as far as I can see includes complete schematics.

[ThaiGuy]

Hey Alm,
Thanks a lot pal.