HP Z440 WORKSTAION PSU

[Koldov]

Came in  last week and turned my old beast of a work computer on, but alas it appeared to be dead...

 

First thought was PSU and I have a few lying around, but unfortunately as with most things HP it's a proprietary PSU, so nothing to test that theory with.

 

I have an old 24/20 pin tester, but it appears this HP PSU has 18 and 12 pin plugs so although they both fit it doesn't turn on, I have no idea if the pinout is standard (I doubt it) and so might just not kick off the PSU_ON pin...

 

I don't have anything to test it with and I can't find any reliable pinout diagram to short the PSU_ON pin myself and I'm not going to stick paperclips in randomly.

 

Anyway, I managed to get a replacement and duly hooked it all up only to find out this didn't work either (wish I could've tested it first)!

 

So, either I'm very unlucky to have two dead PSUs or something else is the issue.

 

However, I did a bit more digging and found the higher spec models have BIST on the back I/O panel, unfortunately the Z440 doesn't but I did notice an LED inside of the PSU itself. Now this doesn't light up on either of the PSUs when plugged in to a socket....

 

So my question is, does anyone know if this should light up when the PSU is receiving power, or only when turning the PC on?

 

I've tried numerous kettle leads and different sockets (and other PSUs to test that it is getting power).