A couple of weeks ago my computer began to either freeze or reboot several times a day. I noticed that it occured especially during some tasks, such as moving large files from one partition to another. I opened my case to observe if anything was wrong. I played around in Windows until it froze again. After that I couldn't get the computer to boot.

When powered on, all fans (case, cpu and graphics card fans) spin and the hard drive also makes the standard sounds. However, the monitor, keyboard and mouse receive no power (the monitor remains in standby mode). There are no POST beeps. The keyboard flashed the first few times I turned the computer on, but it soon stopped doing that.

I installed a new power supply, but it did not fix anything. I removed all components, reseated the motherboard in the case, reseated the CPU etc. but this also had no effect on the symptoms. I removed all RAM sticks to see if I could get some beeps, but unfortunately this didn't help.

So, in short:

- All fans spin
- Keyboard, mouse and monitor receive no power
- No POST beeps

I've tried the following, all of which have had no effect on the symptoms:

- Removed all unnecessary components, aka "bare bones" system
- Reseated all components
- Replaced power supply
- Replaced RAM
- Reset CMOS
- Removed majority of dust

- Powered on without RAM to see if it would beep

What I haven't tried yet that I could reasonably accomplish:

- Replace video card
- Try with the motherboard outside of the case to rule out shorting.

The second one I have questions about, as I've never done it before. On what kind of surface should I place the motherboard on? Will ordinary cardboard do?

What to do in case neither of these fix the problem? Which component is the most likely culprit? I also wouldn't rule out me forgetting to connect some wires while installing one of the components, so even obvious advice is welcome.

hi mate. Yeah take out the board and boot up with a barebone system. Make sure you try the different sticks of ram. Only use one stick but if 1 doesnt work try d other and so forth. Just put it on any piece of cardboard.. thats fine. Motherboard box will do. The amount of times this s&^t happens to me and its always ram...

To start up the pc you wont have ur switch set up, so to power it on and off u have to get a philips screw driver and touch the power pins on the motherboard with it. To shut down keep it pressed for 7 seconds around. If it doesn't start up on contact straight away, keep it held there.

prob ram or power supply.