Agilent E3616A PSU, dead [FIXED]

[HighVoltage]

My Agilent E3616A is from 2007 and suddenly died.
After "turn on", the display shows random stuff and nothing happens on the output and OVP light comes on right away.

I was looking for the schematics but there is nothing on the Keysight website.
It seems like Agilent has pulled service manuals and schematics already in 2007.
http://www.keysight.com/main/editorial.jspx?cc=AL&lc=eng&ckey=1000000367:epsg:man&nid=-536902299.384304.00&id=1000000367:epsg:man

There is the operating manual that even says "Service Manual" on the cover page but is has no usable content for repairing this PSU.

Does someone here might have a full schematic?
 
Thanks.

[Deathwish]

http://elektrotanya.com/hp_agilent_e3614a_e3615a_e3616a_e3617a_sm.pdf/download.html

[HighVoltage]

Thank you Deatwish,
But that one is the same as the one on the keysight website or many others that I found
The oldest one I found was by HP from 1999 and it also does not include the service manual / schematics.
Since this PSU was already made during the HP time, one would think that it is easy to find a good schematics.

I will keep looking.

[HighVoltage]

I found the schematics and parts list here:
https://github.com/ee-lco/e361xa/blob/master/doc/AgilentE361516AManual.pdf?raw=true

The schematics was annotated by someone but it is ok to use.
Now the trouble shooting will begin.

[HighVoltage]

OK, I found a big problem on the rails

U13 is a LM317 and is suppose to be at +15V
Measured 1.2 Volts

U14 is a 7912 and shows no output at all

The input from the transformer seems to be OK.
So, I will exchange those two regulators and see what happens...

[SeanB]

With them out check the input voltages to the regulators and if there is not a short on the output. Strange that both rails go at the same time, I would suspect the output has a short somewhere, or R108 has gone open.

[HighVoltage]

@SeanB
Thanks for the feedback.
R108 was OK
No shortage on the outputs.
All capacitors OK and both diodes (CR31, CR32) are OK

I installed two new regulators and the PSU works perfectly!
Almost too god to be true and a big surprise, but even the calibration is spot on.

To the failure:
Yesterday I used the Agilent PSU to supply 12V at 500 mA to a cascading high voltage DC supply.
I think some high voltage spikes must have traveled back to the Agilent PSU.

So, bottom line... 2 new regulators and couple hours of work and the power supply works like new.

[BFX]

Good job Zum Wohl! :beer: