This post is going to involve 2 PCs, which I will refer to as PC 1 and PC 2. They are identical except for their graphics card and power supply. They both have ASUS P5E board and Intel Core 2 Duo CPU E8400 3.00GHz, 3.25 RAM, running windows XP. They both had the same LG flat screens. Their power supplies were 750's thermaltale but went out a year ago. Unfortunately they were both downgraded
PC 1 ( gforce 8800gt card and a 500 watt power supply )
A month or 2 ago the LG monitor went off and never came back on. My sister had an old vga Mitsubishi diamond plus 91. I didn't have the funds yet to buy a new one so I hooked that up and everything was fine for about a week or two. Then the monitor shuts off and goes into power saving mode. I assumed it was the power supply and it sits waiting for a new one.
PC 2 ( gforce 9800gtx card and a generic 700 watt power supply )
The LG monitor went off and never came back on. I took the Mitsubishi from PC 1 and a week later, the monitor shuts off and goes into power saving mode. I assumed the monitor finally died and I went out and bought a new acer flat screen. I hooked it up and when I booted up I heard 1 long beep and 3 short beeps. The monitor went into power saving mode. I then researched and found that beeping code to be an Award Bios error saying it might be the ram on the graphic card. I pulled the 8800 card from PC 1 and upon boot up I heard 1 long beep and 3 short beeps. Then I found the gforce 8500 that came with my pc originally and put it in and it worked. The beep error was gone, but a couple hours later the new 24" Acer flat screen went into power saver mode. Showing a "No Signal".
Then I found memtest86+ and ran it 7x. The result was 7 passes and zero errors. So I am completely lost. Do I have 2 dead cards and 2 failing power supplies? Where it stands right now is I can boot up and after a few minutes the monitor powers down. The pc stays running. Any help would be so greatly appreciated.