Sun

I know the main focus of the forums here is SGI hardware, but i figured I would ask this here because I'm not really sure of where the best place to get information for sun machines would be. I picked up 2 SUN IPC workstations today from a warehouse.Pretty neat looking little machines. They are both in pretty rough shape, bits of rust on the case and corrosion on some places on the motherboard. They were not stored in ideal conditions. I did alot of cleaning of the motherboards, however upon trying to power them on i get a soft click, a quick flash of a green led, then nothing. Im not sure weather to suspect the power supply or the motherboard, If it's the motherboard i might as well pitch them. The power supply uses an odd short 12 pin cable, i was curious if there is a pinout for this so i could test to see if the power supply is the issue. They both give the same behavior when trying to be powered on. Short click, green light quickly flashes, and then nothing.

At any rate It was worth it just to get a pile of simm memory and a couple scsi disks i can use in my SGI machines.
Any help or suggestions are appreciated.

Since it doesn't look like anybody else has responded yet, I'll offer a couple of comments:

MrBill wrote: I know the main focus of the forums here is SGI hardware, but i figured I would ask this here because I'm not really sure of where the best place to get information for sun machines would be.

Have you tried asking on any of the mailing lists at sunhelp.org ? That's probably the best place to find old Sun info. (And, co-incidentally, the lists are run by a guy who goes by a name similar to your own.)

MrBill wrote: I picked up 2 SUN IPC workstations today from a warehouse. [...] The power supply uses an odd short 12 pin cable, i was curious if there is a pinout for this so i could test to see if the power supply is the issue.

The pin-out for the IPC's power supply can be found in the Sun-4c Handbook .

Check the power supply for leaking electrolytic capacitors. I had the same problem with an IPX that did the exact same thing.
First, make sure you unplug the power supply from the wall, etc.
Once you have taken the power supply out of the box and took off the cover, unscrew the PCB from the metal cage.
There are 3 3300uf capacitors that have probably leaked. They are the tallest caps you see. If you also see a coat of thick brownish color substance on the board where this caps are located which can be wiped up by a Q-tip, that's probably what has happened. All three of mine where in this condition. The other caps where ok but be sure to check all of them just in case.

I unsoldered those caps from the board, cleaned up the board really good with pure alcohol and Q-tips and installed new ones.
I found my caps on eBay for less than 10 bucks for a pack of 5. Make sure you get the correct voltage ratings and orient them properly on the board.

Let me know if this worked out for you.

If you're going to replace capacitors inside a PSU, beware that there are more parameters to electrolytic caps than capacity and voltage. In an SMPS you should use low ESR elcos.

Another important parameter is the maximum operating temperature. Higher max means it will last longer (at moderate temperatures). Use 105deg, 80deg is budget crap.

I've done my fair share of power supply repairs, and I prefer Panasonic FR series. FM series is probably OK also. You can buy them from Farnell / Element14, Digikey, Mouser etc. eBay is more for desperate stuff (components not manufactured for a decade with no suitable replacements available etc).