PC only boots after second try

[grodrigz]

Hi. I'm trying to fix a friend's older PC - one of those no-name custom builds with a AMD Duron processor, running at 946 Mhz. The problem is that about 90% of the time it won't boot the first time, but it will ALWAYS boot if you turn it off and immediately turn it back on (up until 10-12 seconds after turning it off the first time). During the first try you get no beeps, no POST and no video, but the fans are working.

BUT on the second try it ALWAYS boots up normally and works fine until you turn it off and back on again. I've tried just about all I can think of to remedy the problem as I imagine with time it will get worse. Cleaned the contacts for the memory and reseated them (2x128 mb - I know...sad). Cleaned contacts from graphic card, reseated it and replacing it with a known working one. Connected to the onboard video controller rather than the graphic card. Tested the PSU and swapped it with a known working one. Reset the
CMOS by removing the battery. Tested the hard drive, reformatted it and reinstalled OS. I removed all peripherals (cd-rom, floppy, cards, ..etc), running it with bare essentials. All drivers are working properly. Short of a defective motherboard or CPU, can this be caused by something else?

What's odd is that it always starts up when practically restarted immediately after first attempt and it will run fine if used all day.

More specs:
Motherboard: Matsonic MS8308E
OS: Window XP Pro SP2
80 gb Hitachi Deskstar HDD

[Comtech Solutions]

Any chance the contacts for the power button are sticking?

[MLCS]

I had a PC that did this sometimes. I never did figure it out though. It didn't do it to me every time though, just every so often I would restart and it would just sit on the black screen, so I'd restart again and it would boot just fine. Since it was my own PC, and it wasn't a huge problem I ignored it for the most part, being a minor irritation. Would be interested to see what the problem really was though.

[NYJimbo]

Sounds like something has to "charge" the first time. Could be problems with the caps or could be the cmos battery is low. If you can swap out the cmos battery for a known good one that might help. But I have seen this due to caps, cmos and power supply issues.

[purple_minion]

Some of these are very strange and you may never know. I had a computer that if I left the AC on at night during the summer it would die overnight. It simply got too cold... like 64F too cold. lol. I caulk it up to a flaky motherboard and probably some kind of intermittent connection issue like a bad solder joint. If it's livable it's not worth it. My uncle's PC which was cobbled together with some of his old parts and some of mine refuses to shut off the fans on the power supply. Solution... a garage sale under monitor power strip. Done with computer, hit main power button, no fans running and not out another power supply/mother board. (This is under linux and windows so it's a hardware issue not an incomplete shutdown)