Intel Core2Duo E7200
AMD Sapphire 7750 1GB
3GB RAM DDR2 667 (1x1gb and 1x2gb)
Problem: It suddenly stop while I was opening a video editing program. This is not the first time this happened. It's not just with my video editing program that it crashed. It's random. so this time it didn't boot back up again like it did before. When I switch it on the PSU and cpu fans turns on for about 3 seconds then it shuts down. No screen output or beeps.
I tried troubleshooting it by isolating each component and I think it has got to do with my RAM or motherboard. Here's what i've done:
1. Isolated the PSU by turning it on using the paper clip trick. green and black wire shorted. I then tested the 12v and 3.3v railing and it worked fine on my multimeter.
2. Removed the graphics card and turned the system on but the problem is still there.
3. Removed the hard disk drives and it still won't boot up.
4. Removed the RAMs one by one, switched them on both slots, tried using just one RAM and the problem still persists. I've tried removing both my RAMs and the system fans including the PSU will turn on without shutting down but there's a continuous nonstop beep.
Don't know how to troubleshoot a motherboard so I'm down to either the RAM or Mobo that is causing all this.
PLEASE HELP. I'm planning on buying a new pc but I still can't afford it yet.