I have a computer which randomly one day had no display when I came in. I turned it off and back on, and it just kept restarting on me. Turn off, turn on, turn off, turn on.
- Mobo: G41M-P25
- RAM stick 1 & 2:Patriot PSD34G1333KH 4GB PC3 DDR3 10600 CL9 2x2GB 1.5V
- RAM stick 3: Elite 4GB DDR3 1333 CL 9-9-9-24 1.5V (ALL sticks are unbuffered)
- CPU: Dual core E5500 2.5GHz
- HDD: 1TB 7200RPM Western Digital SATA
- DVD drive: Dell DVD-RAM 32x DVD Burner Drive (unplugged for all testing)
- PSU: CoolMax 600W PSU
I thought it was the power supply, and I went out and bought a new one and replaced it, but it still did the same thing.
I took it back and put the old one back in, this time I replaced the mobo. Now the problem changed from endless restarting to no video and no USB power, which is strange. Usually strange problems = RAM problems, so I switched out the RAM sticks one at a time. One of them triggered USB power while the other didn't but no video out, so I switched to internal graphics card instead, and it worked. So my external graphics card doesn't seem to be working either.
Now I have a bad mobo, 1 bad stick of ram, and a dead GPU.
I bought a new stick of RAM online and I turned it on today with the new one in, aaaaand... no video out, but still USB power. I cleared the CMOS and tried multiple combinations of all 3 RAM sticks (the new stick is different brand but has the exact same specs including voltage, timing, speed, everything.)
Still only 1 of the sticks turns the video on, and that RAM stick works in either slot.
| stick 1 | good | DIMM 1 | computer works | | stick 1 | good | DIMM 2 | computer works | | stick 2 | bad | DIMM 1 | no video | | stick 2 | bad | DIMM 2 | computer starts endlessly restarting | | stick 3 | brand new | DIMM 1 | no video | | stick 3 | brand new | DIMM 2 | no video |
Either stick 3 is bad, I suppose it could be the power supply but I unplugged the DVD drive just to use less power and still nothing was working. Then I tried unplugging the HDD too, and still nothing. I tried all 3 RAM sticks and all combinations of the RAM sticks as well.
Using 4 fans to cool the unit.
Do you have any suggestions?