Computer wont turn on

Hey all,

The problem I have is that my computer wont turn on. I have had this problem before but it would only happen once every few weeks or so, I try and turn the computer on but nothing happens. All the other times this has happened I have pressed the power button a few times and then it will turn on, or I have pressed the power button a few times and left it then it will turn on a minute or so later by itself.

Yesterday and today though it has decided to do it again, although yesterday it took about 20 minutes of me pressing the button a few times then leaving it for 5 minutes to come on, and today the same but it just hasnt turned on. There is an LED on the motherboard which lights up all the time even when the computer is off (but not when its unplugged) I think it tells you there is power to the motherboard but I'm not sure. Once the computer is on its fine though, it wont restart or anything.

I have looked on the internet for people with the same sort of problems and the cause for most of them is the power supply, which I think is the same in my case, as I got all new parts for my comp a year ago, except the power supply which I kept and is about 5 or 6 years old.

Does anyone else have any other ideas on what it could be? Or could confirm what I'm thinking? Also if I need to buy a new power supply, should I buy the same one or doesnt it matter?

Thanks for any help

 

This is a comprehensive explanation of how to test your PSU
it will explain it better than i can.

http://aphnetworks.com/lounge/turn_on_psu_without_motherboard_the_paperclip_trick

The other thing you can do is take out the CMOS battery and leave it for 10 min then replace it.

 

What you have perfectly described are the results of bad capacitors on the systemboard. http://www.badcaps.net/pages.php?vid=5

 

Maybe, but my motherboard is only about 1 year old, all the capacitors look fine and I'm not getting any of the symptoms that site says. Once I actually get the comp turned on, its perfectly fine from there it has no other problems and runs exactly how a normal comp should.

The only other problem I get is sometimes when I turn the comp on and it gets to the black screen with the windows name and logo, it freezes there and it looks as though the screen has half power or something, as the display is very dull, and it will stay there until I restart the comp then its fine, this may have something to do with the comp not turning on, I dont know though as I dont think it has happened at the same time I have had trouble turning it on.

 

OK; though sometimes bad capacitors rear their ugly heads much sooner......

The other two possibilities, then, are a failing power supply or an overloaded 5V standby.

The standby voltage can be set to power the keyboard and/or USB ports and, if it is marginally overloaded will cause the system to be flakey, too. The option is usually jumpers or in the BIOS.