computer power supply help

[janetg]

hi all -

have a little problem this morning after a power outage...my main computer will not power up - it starts to, then stops...then tries again, then stop...

does this sound like a power supply gone out?

thanks

[Davidtxs]

Can you get into BIOS (setup) or does it stop before that ?? could very well be ps

[janetg]

no - can't get anything - it literally tries to power for about 2 second...then kicks off - tries again - kicks off...

and thanks for being up this early to help ...

[bullsparade]

Since it is at least poweing up to begin with, I am thinking it's not the power supply as much as something on the Motherboard. As it's powering up (hense PS is working) a circuit on the mobo is fried. It also could be ram that got zapped and as its powering up it dies. Try switching the ram one at a time. In other words pull one stick out...see if it boots. Then put it back and pull the other out.

[janetg]

thanks for that - we knew this might be a buggar to diagnose. it happened about a month ago when we had like 10 power pops right in a row - really surged everything - and i'm on a battery backup - but i was able to reboot finally after around 6-7 tries. i have only powered down once since then without issue -

but this time...nada..

as long as we have to pull it apart, i guess i need to look for bulging things on the MB? then try the ram thing....power supplies are cheap enough - i'd hate to do a new mb though - what a pain!

[bullsparade]

also while you are in there..try reseating your components (ram, video card, sound card, etc...). I hope for your sake its not the MB, as you stated a bit of a pain.

[TXhummer2]

Often, the 12V side of a power supply survives when the 5V side goes. This could very well be a power supply only. If you have a multimeter, check the different outputs on the motherboard feed line, see if only the 5V side is missing.

[Truckman]

The last time that happenned to me, the hard drive was corrupted...Ben

[Davidtxs]

could even be a memory chip if you have more than one try pullin one at a time out and seeing what happends go through how ever many you have like you said its a pain to diag

[haraki74]

The same thing literally just happened to me. The culprit was the on/off switch. Here is a way to check it.

Unplug the power cord and open the case

Trace the wires from the front mounted switch on your case to the motherboard. It's two wires that usually end in a plastic cap that goes over two pins on the motherboard. The cap is usually labeled Power SW. Remove the cap from the pins, but remember where it goes.

Plug the power cord back in

With an insulated flat head screwdriver, CAREFULLY touch it for just a second to the two pins you removed the cap from (you are making a connection between the pins just like your power switch does)

If everything starts up normally, you just found your problem.

You can replace the switch either from your case vendor or just go buy a momentary on/off switch at a local computer supply store. Mine cost a whopping $1.49

While this switch replacement fixed my on/off problems, the constant on/off problem did a number on my hard drive and I had to reformat it. What a pain.

Hope that helps!

[janetg]

so we are trying the power switch thing...and have purchased a new power supply. my next question is...

i don't have to have any drives hooked up once the ps is replaced in order to see if this works, right? if it indeed was the ps - then it will turn on, if not, it won't. correct?

or how do i determine if it is the motherboard? all help is soo appreciated.

[Davidtxs]

yep if it was the ps it will power up and you can get into bios

[janetg]

well, so far so good - it appears to have been the switch only - and man...you can't get those at fry's.. so everything is still in pieces until tomorrow, but it works!

thanks everyone - it's really great to have a place like this where you can get some answers from intelligent folks and on SUNDAY no less - i really appreciately everyone's help and advice!

janetg