Forum Home
Press F1
 
Thread ID: 98560 2009-03-29 06:01:00 Weird PSU problem HorrO (14766) Press F1
Post ID Timestamp Content User
760411 2009-03-29 06:01:00 Hi Guys

Now to start off i wouldnt normally ask for help with fixing a hardware problem but in this case im stumped. It started off with me just adding an extra fan, right shouldnt have any troubles there. after i had screwed it in made sure everything was ok i plugged the PC in and it booted up perfectly. i shut down and moved it back into my room plugged everything in. then bam it turns on for about a split second and then nothing. the PSU LED was off so it was obviously recieving no power or something was wrong (the led was on when PC was off but when i hit the power switch it would immedeatly go blank.) So after several hours of messing around i have noticed that after the power cord is disconnected the LED flashes on and off after about 3 seconds.
any thoughts before i go and buy a new PSU.
HorrO (14766)
760412 2009-03-29 06:07:00 I assume you don't have a spare one to try? gary67 (56)
760413 2009-03-29 06:49:00 Just tried other PSU from older computer, same problem except this time no other fan just PSU Fan. i have checked the CPU fans and stuff 1000 times tried other powerpoints. this is getting a little frustrating HorrO (14766)
760414 2009-03-29 06:51:00 Welcome to PF1

Check that you didn't bump the voltage switch on the back of some PSU's.

Some you can change the voltage from 240 V to 110V ( which is for USA)

IF by some chance the switch got changed the PSU will be dead - 240 V going into 110 does'nt work to good.

Edited: I see you tried another PSU - could have a blown board.

Another thing you can try - remove all connections that lead to the onboard USB's and front panel header - locate the two pins that the on Button uses, short them with a small screw driver, this will cause the PC to boot - if it boots then kill the power and replace each set of connections until it stops booting again.

Had just on Wednesday a customers PC that the front USB ports were shorting and stopping the PC from starting.
wainuitech (129)
760415 2009-03-29 07:23:00 basicly what i have at the moment is only what needs to be connected for a computer to boot up. so video cpu ram psu hooked up thats it. im thinking motherboard problem now. i tried the screwdriver earlier today and the same thing happened. what i find strange is that i moved it from one room to another and it just doesnt work anymore. HorrO (14766)
760416 2009-03-29 07:25:00 and my psu doesnt have the voltage switcher on it so theres no problem with that HorrO (14766)
760417 2009-03-29 07:40:00 Have you tried disconnecting the new fan, may have the positive-negitive the wrong way around. jebby (4580)
760418 2009-03-29 08:29:00 Have you tried disconnecting the new fan, may have the positive-negitive the wrong way around.

Yea mate, if ya read the post above all i have plugged in is what i need to have in for a pc to function, ie ram cpu mobo. but i know think this is a motherboard problem considdering this has happened on both PSU's i have tried.
HorrO (14766)
760419 2009-03-29 08:38:00 Just in case something weird has happened , remove the board from the PC, on the bench have only the PSU, CPU, RAM & monitor plugged in see if it will boot out of the case - you can also try removing the CMOS battery and replacing it - it may have gone dead all of a sudden.(stranger things have happened) wainuitech (129)
760420 2009-03-29 11:33:00 Thanks for everyones help, im leaving it for tonight then ill try your suggestion wainuitech. Till then please dont hold back from replying as i really dont wanna have to buy a new motherboard. HorrO (14766)
1 2