PC problems

[alfio]

hello all

we've had an old custom built machine running as our media center for some time and it was working fine until a few days ago. first starting became a problem: push the ON button and it would take 2 or 3 attempts until it cycled through normally (when it didn't the power supply would go on alone as if there was no motherboard/HD connected)

yesterday it stopped turning on altogether. the ON button by itself (i.e. pushing and releasing as one would do normally) does nothing. if i hold the power button down, it begins to start normally (i.e. fans spin and the HD light goes on) but it then dies.

my original thought was that the power supply was bad and i tried swapping in an older (working) unit but that had no effect.

any ideas? thanks folks

[Neil]

Maybe the power switch (usually a momentary contact) itself is bad. I've had it happen once.
You could test by removing with switch wires from the motherboard, and shorting the power pins momentarily with a screw driver or something similar, and see if it starts normally.

[ganon11000]

try using different ram sticks and mixing them up. also short out the power switch pins on the motherboard (front panel header) you could also try removing / swapping the GPU as that could be failing and shorting out?

[alfio]

Maybe the power switch (usually a momentary contact) itself is bad. I've had it happen once.
You could test by removing with switch wires from the motherboard, and shorting the power pins momentarily with a screw driver or something similar, and see if it starts normally.

power switch tests fine, will try the shorting trick and see if i've missed anything

[alfio]

try using different ram sticks and mixing them up. also short out the power switch pins on the motherboard (front panel header) you could also try removing / swapping the GPU as that could be failing and shorting out?

unfortunately i don't have a backup GPU. come to think of it, don't think i have extra RAM either.

you suspect the GPU or RAM because the BIOS won't post?

[ganon11000]

try using different ram sticks and mixing them up. also short out the power switch pins on the motherboard (front panel header) you could also try removing / swapping the GPU as that could be failing and shorting out?

unfortunately i don't have a backup GPU. come to think of it, don't think i have extra RAM either.

you suspect the GPU or RAM because the BIOS won't post?

It is the biggest issue for the bios not posting. normally the GPU but it can be RAM. Do you have a buzzer connected to the motherboard? (to hear error codes)

[alfio]

after spending a little more time testing the computer, i'm more confused than ever

i pulled the wiring to the ON/OFF switch and got it to start by shorting out the terminals on the mobo. it still doesn't want to start and for every one successfull starts, i still get three or four failed starts but i got it started nonetheless. problem now is that it won't stay on for long. after a while the whole thing freezes up and crashes. any ideas?

[ganon11000]

after spending a little more time testing the computer, i'm more confused than ever

i pulled the wiring to the ON/OFF switch and got it to start by shorting out the terminals on the mobo. it still doesn't want to start and for every one successfull starts, i still get three or four failed starts but i got it started nonetheless. problem now is that it won't stay on for long. after a while the whole thing freezes up and crashes. any ideas?

Ok, GPU is fine. Try different ram and reseating everything. If that doesn't work a board replacement is in order!

[jronald]

http://www.badcaps.net/

Take a look here.

Ron

[alfio]

after spending a little more time testing the computer, i'm more confused than ever

i pulled the wiring to the ON/OFF switch and got it to start by shorting out the terminals on the mobo. it still doesn't want to start and for every one successfull starts, i still get three or four failed starts but i got it started nonetheless. problem now is that it won't stay on for long. after a while the whole thing freezes up and crashes. any ideas?

Ok, GPU is fine. Try different ram and reseating everything. If that doesn't work a board replacement is in order!

tried with different ram and got the same results. you sure a new mobo will take care of this? thanks!

[DaKKS]

Id bet on the board as well. Sounds like blown caps. Jronald linked a good site.

[ganon11000]

tried with different ram and got the same results. you sure a new mobo will take care of this? thanks!

new mobo is easiest but replacing caps / the bad part is usually cheaper, having said that if it's atx / micro-atx you could upgrade it to an i3 or better for ~£130 on eBay:
http://www.ebay.co.uk/itm/INTEL-CORE-i3 ... 1c3398e193