Pentium Pro mainboard not working, please help!

[PetroffHeroj]

Hello, folks.

Recently got a Pentium Pro mainboard; processor included, 4 72-pin SIMM
slots, built-in audio (some Crystal) and MIO, and so on -- yer olde server
brand from the middle of the 90's. The power supply wasn't included, neither
was the case or any peripherals, except for the bus multiplexor: the board
has only one EISA-lookalike slot, where you stick the multiplexor to get 3
PCI and 2 ISA slots.

After hooking the board to a usual AT power supply and sticking in a video
card and some SIMMs, I turned that mess on, but nothing worked for me. One
of the video cards kept giving some skewed retrace and garbage (anyway, it
looked like dirty white diagonal stripes running down the screen), and
others were just black. The keyboard didn't get init'd (stayed with LEDs
on), the speaker was silent even after I took away all memory modules and
later the video to see if BIOS complains -- the board was silent.

Now, the funny thing is that, although having an AT power connector (vs
ATX), it also features an extra one labelled "STD 3.3V". That one looks
exactly like one of the two AT connectors and neighbours them closely. I was
told it was, ahem, "optional". But the board originally used it (of course).
But that power supply with an extra dangle is long gone.

Could it be that the board is not dead, and I just have to get a power
supply from a more or less similar brand to make it work? In that case,
would any such power supply do or not?

There are also a couple of connectors that might be crucial to the board's
operation. One of them is in the line with the usual pins for speaker, LEDs
and stuff, and is named "SW_ON/SLP" ("switch on/sleep", I guess), and has
four pins. The other is 3-pin and looks exactly like a an-board fan
connector; that one is labelled "S-OFF". May be I've got to short-circuit or
pulse some of the pins on those to get the board alive?

Any comments will be really appreciated. Pentium Pros were rare beasts even
back then when people actually heard of them once in a while (1995-1997),
and these days laying my hands on that board was a real miracle. Suffice it
to say that it's the first Pentium Pro CPU I saw face to face :) The guy
must have pumped iron a lot judging by its size ;) Anyway, it's no wonder I
desperately want to see that thing working.

So far all I got is that the CPU _heats_ somewhat after several minutes of
(non-)operation. So may be the board is not dead after all?

Thanks!

Leonid

[Charles Howse]

Previously PetroffHeroj <forged@address.net> wrote: Hello, folks.
Recently got a Pentium Pro mainboard; processor included, 4 72-pin SIMM slots, built-in audio (some Crystal) and MIO, and so on -- yer olde server brand from the middle of the 90's. The power supply wasn't included, neither was the case or any peripherals, except for the bus multiplexor: the board has only one EISA-lookalike slot, where you stick the multiplexor to get 3 PCI and 2 ISA slots.
After hooking the board to a usual AT power supply and sticking in a video card and some SIMMs, I turned that mess on, but nothing worked for me. One of the video cards kept giving some skewed retrace and garbage (anyway, it looked like dirty white diagonal stripes running down the screen), and others were just black. The keyboard didn't get init'd (stayed with LEDs on), the speaker was silent even after I took away all memory modules and later the video to see if BIOS complains -- the board was silent.
Now, the funny thing is that, although having an AT power connector (vs ATX), it also features an extra one labelled "STD 3.3V". That one looks exactly like one of the two AT connectors and neighbours them closely. I was told it was, ahem, "optional". But the board originally used it (of course). But that power supply with an extra dangle is long gone.
Could it be that the board is not dead, and I just have to get a power supply from a more or less similar brand to make it work? In that case, would any such power supply do or not?
There are also a couple of connectors that might be crucial to the board's operation. One of them is in the line with the usual pins for speaker, LEDs and stuff, and is named "SW_ON/SLP" ("switch on/sleep", I guess), and has four pins. The other is 3-pin and looks exactly like a an-board fan connector; that one is labelled "S-OFF". May be I've got to short-circuit or pulse some of the pins on those to get the board alive?
Any comments will be really appreciated. Pentium Pros were rare beasts even back then when people actually heard of them once in a while (1995-1997), and these days laying my hands on that board was a real miracle. Suffice it to say that it's the first Pentium Pro CPU I saw face to face :) The guy must have pumped iron a lot judging by its size ;) Anyway, it's no wonder I desperately want to see that thing working.
So far all I got is that the CPU _heats_ somewhat after several minutes of (non-)operation. So may be the board is not dead after all?

It is a beautiful CPU and the first that does CPU caching for more
than 256MB (?) of main memory. We had two with a scary half gigabyte
of memory a long time ago for some scientific computations. I remember
that we had regular AT power supplies on then, no special 3.3V lines.

Sorry, apart from that I cannot help you. But the CPU also makes
a very nice pice to show, with its gold-plating and all.

Arno