Try giving all the ram/card contacts a good clean with 99% Rubbing Alcohol. Check your IDE cable too and make sure its installed the right way. I think iv had a PC once that didn't wanna boot with a wrongly inserted cable. Weird stuff can happen. Go back to the original PSU if it still works, maybe. I know some OEM builds from Compaq/Dell had proprietary PSU wiring or whatever despite looking like common ATX/AT connectors. Bad caps can always be a culprit ofc, you would have to check that with a multi meter and some tools.

Sorry if that is not much help. I'm not very good at diagnosing some of these issues from afar.

Lots of good advice was given in your previous thread: Dead PSU with no +3.3vdc and fried motherboard
The 3,3 probably wasn't the issue. But your board might have been killed by your failing PSU. As said in that other thread, test with a simple P133 and read out voltages on the board.

flupke11 wrote on 2022-04-21, 07:46:

Lots of good advice was given in your previous thread: Dead PSU with no +3.3vdc and fried motherboard
The 3,3 probably wasn't the issue. But your board might have been killed by your failing PSU. As said in that other thread, test with a simple P133 and read out voltages on the board.

I completely forgot about that thread. This new problem is related to the replacement motherboard that I got on ebay and the replacement PSU that I bought new. I'll have to read through that older thread to see what people were saying about the 3.3vdc lines.

This new PSU has those lines and I've had them going into the motherboard, unlike with the old PSU where there were no 3.3vdc connected to the MB.

EDIT: Damn, I don't know why I forgot about that old thread but this new problem is pretty much identical to the old one, except here I used a new PSU. Incidentally the same PSU that I used on the old MB after the old PSU died.

My Fujitsu-Siemens D990 onetime just lost BIOS. I set BIOS recovery jumper on motherboard and check there some activity on floppy drive. Write BIOS update/recovery floppy, check it with same floppy drive a successfully recover BIOS.

Here the BIOS floppy creation tool

My DFI 586IPV lost it's bios wille loking for a compatible sdram module. No beeps, blank screen and only FF on the post card.

GOLDEN! I will give this a try tonight. Perhaps this is what happened to both my motherboards? I'll report back 😀

EDIT:
I couldn't wait. I've made the floppy , set the jumper and booted with the floppy in the drive.
There is no image on the monitor. Still black, but the floppy is occationally doing something. The readme.txt on the disk says to follow the onscreen instructions 😜

I BE DAMNED! IT WORKED!
I have to try this with my "dead" motherboard as well 😜

Thank you everyone, and especially Babasha for letting me know about this (as well as hooking me up with the correct tool for making the floppy). This has really made my day, guys/gals 😀

One question:

I panic-bought a brand new PSU today. A corsair RM550x. It should have plenty of amps going to -12v etc. (no -5 though), but should I pull out the 3.3v pins so that they are not connected to the motherboard? Since the original PSU didn't have these pins connected, or am I just panicking a little here?

NevilClavain wrote on 2022-04-21, 10:10:

GOLDEN! I will give this a try tonight. Perhaps this is what happened to both my motherboards? I'll report back :) […]
Show full quote

GOLDEN! I will give this a try tonight. Perhaps this is what happened to both my motherboards? I'll report back 😀

EDIT:
I couldn't wait. I've made the floppy , set the jumper and booted with the floppy in the drive.
There is no image on the monitor. Still black, but the floppy is occationally doing something. The readme.txt on the disk says to follow the onscreen instructions 😜

I BE DAMNED! IT WORKED!
I have to try this with my "dead" motherboard as well 😜

Thank you everyone, and especially Babasha for letting me know about this (as well as hooking me up with the correct tool for making the floppy). This has really made my day, guys/gals 😀

Be aware this disk is for Fujitsu-Siemens D990 motherboard only. Yes, it works in blind mode if you recovery using jumper. I am a D990 expert))) Nice board with interesting upgrades, do you have one (video RAM, wavetable or maybe original Siemens PCI multimedia board)?

The old board didn't recover. No activity on the floppy. But the new one (the one this thread is related to) is back in working order. I have three of these machines now. I love it SO much. I have wavetable-chips installed in them, and have considered a video-memory upgrade, but I haven't heard about this multimedia board. What is it?
And do you know exactly which of the many Matrox memory upgrades are compatible with these motherboards? I assume it would be the matrox mystique memory upgrades. Those are quite hard to find.

This really is the perfect 90's gaming machine.

It compatible with original Matrox Mystique 2Mb memory module (not Millenium series, or Compaq Matrox Mystique).
Multimedia board is PCI tv/fm tuner and 3d sound spatializer board. I find only box image in pure quality sometime ago on ebay.de

Photo Siemens Multimedia board PCI

Wow, that's a chunky looking card. Thanks for sharing! 😀
Those must be incredibly rare. My googling turned up practically nothing on this thing