Asus p5q won't detect a specific (functional) video card

[KiriKaeshi]

Hi,

I hope someone can help me with an issue I have with my old motherboard. I usually leave the computer on over night and this morning I found it on, but with no image (monitor behaved as if the computer were turned off).

I switched the computer off using the power button and when it tried to boot I got 1 long, 3 short beeps. I tried plugging the video cad (AMD R7770) into another computer and it worked fine. So next, I tried using an old video card (nVidia GTS250 if I'm not mistaken) which had an overheating problem, and the motherboard recognized it fine. At first, windows started normally, but soon the screen went black again.

So I decided to take the motherboard out of the case, I cleaned everything and reconnected. But my AMD card was still not recognized by the motherboard and when I plugged an (admittedly faulty) nVidia, BIOS and booting sequence was displayed normally, but once the windows log in screen appeared, I could only see a narrow strip on the top of the screen. But this is probably due to the card being faulty itself.

Finally, I tried to switch cards from my two computers. So I plugged in nVidia GT430 into ASUS p5q and so far it works perfectly. AMD card works equally fine in my other computer.

Can somebody explain what is going on? Is it suddenly rejecting AMD hardware? Could my motherboard stop functioning completely? Is there a way to fix it or do I have to consider finally upgrading my computer (well, buying a new one really)?


Thanks!

 

[JimF_35]

I believe this could be a power supply issue. Does your old video card use PCIe Power connectors? My guess is no and that is why your old card works. Try taking the power supply out of the computer that does work and installing it into your new computer to see if it solves the problem. I could be wrong though.

Translation of the code from the user manual...

One continuous beep followed by three short beeps -> No VGA detected

 

[KiriKaeshi]

I believe this could be a power supply issue. Does your old video card use PCIe Power connectors? My guess is no and that is why your old card works. Try taking the power supply out of the computer that does work and installing it into your new computer to see if it solves the problem. I could be wrong though.

Translation of the code from the user manual...

One continuous beep followed by three short beeps -> No VGA detected

You're right, the card I'm using now doesn't use PCIe power, but gts250 does and it got recognized by the motherboard. It even worked somewhat, although I can't be sure if it malfunctioned because of the overheating problem (for I brief time I used it, it got almost too hot to touch) or due to possible PSU fault.

PSU was what I initially suspected, but it's a new one, I got it 2 weeks ago and it worked perfectly so far (EVGA 500W). I was initially worried that it might not provide enough power to the system, but I haven't noticed any problems until now (and I tried using it with only CPU, GPU and memory connected - in case HDD's are weighing on the system). Is it possible that grid voltage is causing this? How can I test for faulty PSU? Since it's under warranty, I could probably replace it.

For now, I think I'll follow your advice and switch PSU's as well, thanks!

Edit: I finally got around to switch PSU's and the same problem persists...