System freezes, then won't reboot.

[mista2turbo]

I have been fighting this problem now for about 2 weeks with mixed results. It started with my computer just not starting one day. No POST. I've had video card related issues in the past and gave that a shot. Swapped it out and tested in another machine. OK. Then the machine started. It ran about 10 minutes and then cut off. Determined it might be a cooling issue. So i bought a new fan and heat sink installed them, and blew everything in the case clean. Machine ran good for a couple of hours, doing normal activities, internet browsing, played City of Heroes for a few minutes. Then after a while i decided to load up a new game i had picked up. During the install of this game the system froze. Would not reboot, same as before. no POST. At the point i gave up for 2 days. Yesterday i decided to swap parts between machines one at a time to try to find a bad component. CPU fine, HDD fine, Vid Card fine. Could not swap RAM due to different formats. Reassembled my machine, and everything ran good. This was about 3:30 pm. Used the machine off and on through out the night. It stayed on the whole time, went into sleep mode when it should have, nothing out of the ordinary. Then this morning I went to finsih loading my game again. It loaded fine, but when i went to start playing it the system froze. Same as before, will not start up. No post no video, fans run. Any ideas??

P4 2.4, 512megs DDR266, geforce4 4200, soyo dragon MB

[ski]

Check the MB for bulging, leaking, or ruptured capacitors(small upright cylindrical components).
If you find any, then replace the MB.

If there are no defective capacitors, then make sure all connections are secure, and reseat the RAM.

If no luck, then remove all cards(except the video card), all drives except the HD, and all peripherals.
If that works, then replace all removed components one at a time, and test after each one is replaced. If the problem reappears, then the last component replaced is the likely cause.

If that does not work, then check if the case is overheating by removing the computer's cover, and running an external fan.
If this fixes things, then install an additional case fan or 2.
Recommended locations are upper rear(or top) of the case blowing out, and lower front blowing in.

If an external fan does not work, then place the MB on a piece of cardboard.
If this works, then make sure there are no metal standoffs where there are no mounting holes in the MB, and check for loose metal objects behind the MB.
If those are ok, then install paper washers made from a manila folder between the MB and all metal standoffs and screws.

If placing the MB on cardboard does not help, then either the RAM, MB, or power supply may be causing the problem.
Either swap them out or have them tested .
You can also test the RAM with Memtest-86:
http://www.memtest86.com/

[ziba-june]

Hi,

Check your Powersupply to see if it work properly, check it a few times for consistancy.