Hello,First let me thank this community for making this place the best reference I've found on the net. All the problems I've had in the past were resolved in here without having to post a single thread.Unfortunately,though,I haven't found an answer nor specific fix to my current problem so here I am. Here's the problem. My computer has got this strange behavior where,all of a sudden,without having altered a software nor hardware component decides to shut down,then reboot,then sometimes Re-Reboot before the POST even completes and so on,sometimes repeating over and over without getting further,leaving me no choice but to shut down my power bar. I find it strange because,it doesn't only shut down or reboot but after a few hours(sometimes minutes) it actually opens up by itself randomly as well. It also happens sometimes when I re-open the power bar on which the PC and it's compnents are plugged. That said,this started to occur a few months ago,and after passing the PC under a battery of the following tests; Antivirus&other malwares detection, diagnostics software such as Sandra(checked also CPU FAN SPEED which was at 4000 something rpm), 2nd Check this time inside the Bios for CPU FAN SPEED,(4000 something rpm again) CPU Heat was checked and very low,about 40F Cleaning Up completely both fans inside the Power Block and on the CPu and making sure they work fine, Verifying if all Hardware is fully functionnal, Checking in the AutoExec.bat file for any Win.com switches, Formatting the HD,changing the MoBo battery,disabling Wake-On Lan(even if unnecessary). ...someone advised me to change the powerblock from 200 to 350W,which I did...The Computer worked wonderfully since then and I seemed to have nailed the problem until last night,after a year or so, where the nightmare returned. The Computer had worked well for more than 2 years before this first started to happen. I've heard of frequent reboots happening when the power supply and or CPU Fan is stuck causing Overheating but Startups/Power On,I haven't. Configuration: Windows 98SE(Power Management 'Always On') Intel 440Bx Pentium 3 450mhz, 196Mb of RAM, Efficient Network Speedstream DSL modem D-Link Eth Card Ati Radeon 7000 Built-In Ensoniq Soundboard LG CDR-W LG CD-Rom 1 USB Gamepad 350W power Supply Cheers, -Steff

Possibly the start button. The ATX power button is a momentary contact switch. Maybe its perlilously close to making contact, and sometimes actually does make contact, causing your problem. Other possible causes: It's almost always hardware problem and is usually motherboard related, but could be a power supply on it's way out - again. Try reseating your memory and expansion boards. Check all drive and power cables to be sure none have come loose. Make sure the CPU is fully seated. Check for a loose printer cable. Sometimes caused by caused by the cpu overheating too.

Thanks for the quick response. I'll check the ATX button from inside,right now,from the outside,it seems stable enough whenever I touch,move or half-press it. It is not an overheating issue unless my bios and Sandra did not detect the heat and Fan speed correctly. Is it possible that one of my memory card is not working anymore?? If so,has anyone had this experience where the PC opens up in the midlle of the night or at another moment when the memory is dead? Cheers, -Steff

I just checked inside,I unplugged/replugged some cable and checked some other. Also,how could it be possibly an overheating problem since the PC can be been off for hours,then suddenly turn on all by itself? I'm clueless and waiting for any kind of advice. Cheers, -Steff Cheers

Check your BIOS for a "Wake On" condition of some sort. Some machines will auto power on after a power glitch. Maybe a loose wall socket / plug. I've never seen a bad memory stick cause this kind of problem. I have seen a flaky case power switch do this, though. Might check the wiring to this as well for a possible short. Don