PC Won't Boot With 5i25 Installed

This is my first LinuxCNC project, so I apologize in advance for my ignorance.

The PC I am trying to use has an Asus P7P55D-E PRO motherboard. I have LinuxCNC installed on this PC and it seems to be running OK. My problem starts after I install a Mesa 5i25 PCI card. When I power up the computer, I see some initial signs of life (fans run, LEDs on 5i25 light briefly, some of the motherboard LEDs light, and the hard drive sounds like it has started up), but that is as far as it goes. The normal sequence of motherboard LEDs never completes. No sounds come from the computer speaker. Nothing appears on the video monitor.

Here is what I have tried so far:
-- Clean PCI slot connectors: No change
-- Install 5i25 in the other PCI slot: No change
-- Change out computer power supply:
-- Corsair VX550W [original]: On power up, fans run, some LEDs light. After a few seconds, fans and LEDs all turn off.
-- Corsair CX500: On power up, fans run, some LEDs light. Fans continue to run and LEDs stay lit indefinitely.
-- Corsair RM1000X: [Same as CX500]

I also went through the BIOS to see if I could disable anything I don't need, but I didn't find anything that looked promising.

Please note that I have installed the 5i25 card in a much older PC and it boots up normally.

Does anyone have any suggestions for me?

Best regards,
Andy Hall

Is it onboard video? The two led's blink red on boot is normal. That means 3 volt bus is good.

Try disabling the onboard video and putting in a video card and see if that does it. I had issues with 5i25 recently, and of course it ended upo being the computers. One I got working by changing video cards the other was bad 3 volt bus.

IF you access to a different PCI card try it in the Asus M\B, there may be a an issue with the PCI slot/slots.

From the PCI standards it was 32\64 bit.

PCI was a great replacement for EISA slots, weren't they fun...hahahha

My thanks to those who have replied to my post so far. Here is a summary of where things stand:

-- So far, I have only installed the 5i25 without connecting the 7i76 so we should be able to rule out a jumper configuration problem.
-- I confirmed the old PC still boots with the 5i25 installed in it, so the 5i25 card is probably OK.
-- The Asus motherboard I am trying to make work does not have on board video, so that possibility is ruled out.
-- Regarding the PCI slot type: The motherboard manual describes the PCI slots I am trying to use as "PCI". There are also PCIEx16 and PCIEx1 slots, but the connectors for these are not compatible with the 5i25 card. Please note that the PCI connector on the old computer looks exactly the ones I am trying to use on the Asus mother board.
-- I just flashed the Asus motherboard with the latest BIOS and confirmed the BIOS did actually update. Sadly, this had no apparent effect on the problem.

I am going to try to dig up some other PCI cards to try. I hope to have more results to report later.

We have found certain Motherboards (mostly older server type MBs ) will not boot with the 5I25. We have not been able to pin this down but it seem to be BIOS related.

Did you try changing any pci related bios settings?

Try a different video card.

Did you try both PCI slots?
PCI 1 is interrupt connected to lan and others.

And did you try PCI configuration in bios.

Are there any beeps when you start?

Thanks for the suggestions. I have already tried both PCI slots: No difference. Boot does not proceed far enough for beeps. I don't know where to start with PCI configuration. The MB manual was no help here.

br,
adh