SGI: Hardware

Info plate from the 060-0027-002 rev A. Obvious difference is the +3.5 line to the gfx is pushed up from 36A to 48A.

Regards, Adam

Great to know, your psu model is dual head, and according to the serial, the latest one they produced. Regarding to this: http://techpubs.sgi.com/library/manuals ... 01-001.pdf , one can have: Solid/Solid, Solid/High, and Solid/Maximum combination in dual head config, so i'making an dumb assumption they allocated 12 amps for the extra Solid gfx. Which again dumb guess, you can drive 2 x Solids with the less powerfull psu, possibly. So if the power eating of an Solid is ~12A, Maximum can go up to 36A, then High should be something in between like 24A, but i will measure this precisely when i start with this mod.

The Impact Video option also uses that power rail.

Just a quick update. Started to reverse engineer the hv board. Yes I know it is probably overkill, but being curious I just need to understand this PSU.

The PCB is a 4 layer FR4 construction, so does pose a bit of a challenge. Through hole components on the top layer and surface mounts on the bottom.

To help generate a net list, I sent the board to be x-rayed. Useful info, but there are so many large caps and wire wound components (with flying leads) that a lot of the detail is obscured. The big heat sink doesn't help either.

So currently striping off the large components. Will also allow me to check the suspect caps. Once this is done I'll send back for more x-rays.

Slow going, managing about 30 mins a day...

Regards, Adam

Good work, I'll keep an eye on progress for sure!

what about reengineer the whole PSU from scratch?
having requirements, constraints, acquiring solid skills with 400Watt PSU

ivelegacy wrote: what about reengineer the whole PSU from scratch?
having requirements, constraints, acquiring solid skills with 400Watt PSU

Might end up being the case, but requires some understanding of what the current on is doing. Currently don't know the start up sequence.

Regards, Adam

What about dynamically measuring all the currents and voltages which are flowing throught the power connector into the motherboard? (which should be functionally equivalent to a black box " black box "), with programmable multimeter? In case, I might help, I have a programmable multimeter, I can have the full control through the serial port in order to do data- sampling (up to 100Khz), etc, unfortunately it's 1 channel 50V-DC@20A, but I can also control my DSO, I have realized a backend to its interface, it's 2 channels @ 100Mhz.

I am not skilled about 200-400Watt-PSU, I have realized things below 20Watt (Switching + LDO)

ivelegacy wrote: What about dynamically measuring all the currents and voltages which are flowing throught the power connector into the motherboard? (which should be functionally equivalent to a black box " black box "), with programmable multimeter?

This is a good strategy, unfortunately my PSU is dead, so can't black box. Current plan is to repair, but repairing requires fault finding and fault finding requires understanding of expected response.

If I get it working I will do some black box testing. I have access to several 4 channel giga-sample scopes (not mine, but I can borrow), so would be possible.

I've built switch mode supplies up to 100W, but would struggle to get something anywhere near as fault tolerant, robust or compact as a commercial unit.

Regards, Adam

Rhodamine wrote: This is a good strategy, unfortunately my PSU is dead

Understood. I thought you had a second PSU. Or another Indigo2 machine,
while I currently do not have an Indigo2 machine (but I might borrow)