I have an asus P5B-E motherboard with four 1GB sticks of RAM. I had an E-VGA 7900GS video card installed. Last week, suddenly, the computer stopped responding and the display went dark (during normal usage). When attempting a cold restart of the machine, it would not post and instead yielded 1 long beep and 3 short beeps.
My research suggested that this was either a memory issue or a video card issue. I tried they video card in two other machines and they would not start with the card installed. I therefore ordered a new BFG 7900GT video card and installed it. Now, the computer still posts with 1 long beep and 3 short beeps.
However, now, sometimes the computer still starts up as normal and runs fine and sometimes it doesn't. Also, the BIOS and OS now only show 2.43 GB of RAM. I've tried pulling the memory out 2 at a time. When I do that, no matter what combination of 2 sticks is in there, it shows a full 2048MB or RAM. However, when all four are in there, it only shows 2.43 GB.
In addition, if I do warm restart of the computer, it posts with the normal single beep.
Any ideas or any tests I could perform would be appreciated.
Jut some more information. I removed the BFG card and put in an ATI Radeon card into the same PCI express 16 slot. With that video card and 4 sticks of RAM in there, the computer boots up and posts with no errors (single beep). Also, the bios now shows 3Gb of RAM, but this board never reported a full 4Gb anyway. The only thing I changed was the video card. One important thing to note is that the 7900GT requires a power supply connection whereas the ATI card does not. Could this mean the power supply is actually causing the problem and is manifesting in the form of a memory or video problem?