PC will not boot at all.

[Grint2007]

So I recently got this problem with one of my PC's. It has been working fine ever since we got it about 3 years ago (So it's not TOO old) Just today, it was running fine, then...dead...
Completely stopped working. Monitor turned off, fans stopped moving, hdd stopped working, everything except the LED on the front of the computer... I unplugged the power, plugged back in, the PSU light came on, but... still no power to the computer. I took the PSU out and put another one in. Nothing. I'd like to know whats going on. The old PSU was I think a 300 Watt, and the new one is 550 Watt, so It's got more power, but still - Nothing. Any help would be appriciated

 

[mc-dexter]

wow... im pluzzled too mate, my guess would of been the psu.... i know its silly but you definately turned the power switch on both at the wall and also on the back of the psu if it has one... not be the first time i've forgot to turn it on there, lol.

EDIT: Obviously try that on your newer psu as if the old 300w one is dead.. then it aint guna be no use doing that

 

[Grint2007]

I've done everything that would cause it to not work. I've turned on the switch at the wall, turned on the switch on the PSU, and I've actually amde sure it is plugged into the mobo, so I've got no clue what it could be..

 

[mc-dexter]

depending on how old it is? is it needing the 4pin for the CPU?

 

[Grint2007]

It's one of the newer models, newer as in it's about 3 years old. It's a compaq Presario SR1811NX to be specific, and yes it does need the 4 pin for the CPU. I'm actually wondering if it could be the Mobo, or the CPU. But it seems unlikely that it would be working fine one second, then the next second, everything fails and just dies...

 

[mc-dexter]

it happens i've had two mobo's die on me all of sudden, they had power going through to the CPU, fans span and everything, but no post screen or anything.

 

[A Cheese Danish]

Are there any lights on the mobo to tell you there is power running through it?

 

[mc-dexter]

have you tried powering up the mobo on its own with no other devices connected, not even the cpu or ram.

 

[Grint2007]

Nothing at all is on. There is no light on the PSU to tell em whether it's working or not... Even with my other PSU, no lights or anything. Is there a chance that both of my Power Supplies are dead?

 

[Grint2007]

I have not actually tried that, I might try that now to see, but I dunno..

 

[mc-dexter]

there is always a chance, my psu's never lit up before, try it from a diffrent power point, without using an extention cable if you are using one,

 

[A Cheese Danish]

Well, if you want to see if they are, take a paper clip, and put one end into a black or ground wire on the 20/24 connector, and one on the green wire.
You should take caution and put some electrical tape round the paper clip just for safety reasons.

But if you said the fans and stuff spin then your psu's should be fine. Could it be over heating? Is it clean?

 

[Grint2007]

Tried it from another outlet, no extension cord, I've tried unplugging everything aside from the actual Mobo, still. Nothing. I'm about to try another PSU to see if that works, and then I'll report back, But I still don't know

 

[Grint2007]

No, nothing works. The fans don't spin, the hard drives dont work, nothing. Could it even be my Power Switch?

 

[mc-dexter]

how can it be your switch if you've tried it on a diffrent power outlet, how sure are you the third spu you just put in even works, remember, you want everything taken off the mobo, maybe one case fan or something so you can see it spin when powered up, or if your mobo has a light on like most do then that'll be easier, less on the mobo is always better for testing anything.

 

[Grint2007]

Well, I've discovered something. After sticking my other PSU in, everything unplugged, it worked. The power light went on, the PSU fan turned on. But the strange thing is, this is the PSU that the computer screwed up with in the first place. Wtf?

 

[mc-dexter]

and you definately had EVERYTHING unplugged when testing the other PSU's?

 

[AsRock]

How about striping the computer check for bad caps burn marks or a like. Then put the thing back together if nothing looks wrong as some times striping a computer can fix them due to things like dust..

 

[Grint2007]

I did. Everything unplugged. But for some reason, I've plugged back in the original PSU and if works fine now, the only problem is, I've read that others have had the same problems, and everything has screwed up like my computer. Then eventually it worked for them. But a few hours or even weeks later, it hit again. But, if it happens again, and doesn't respond after an hour Or so, I'll go on this site again, ask some more questions, and if not, take it to a shop. But thanks all for your time.

 

[mc-dexter]

anytime, happy to help any way i can

but as AsRock pointed out something i forgot.... Dust can be a major cause of problems, so maybe all it needed was a bit of dust being moved.... maybe you should get a unused paintbrush and dust the board and parts down while its out the case, not do it no harm thats for sure, lol,

EDIT: when i say dust motherboard and all the other parts i mean EVERY other part

 

[AsRock]

I did. Everything unplugged. But for some reason, I've plugged back in the original PSU and if works fine now, the only problem is, I've read that others have had the same problems, and everything has screwed up like my computer. Then eventually it worked for them. But a few hours or even weeks later, it hit again. But, if it happens again, and doesn't respond after an hour Or so, I'll go on this site again, ask some more questions, and if not, take it to a shop. But thanks all for your time.

Maybe the PSU is tripping off and by leaving it a while it's returning to normal. I'd check for shorts and bad connections.

Be carefull what kind of brush you use as some of them carry static.

 

[Grint2007]

Yeah, we'll see how it goes. I do have access to a machine that blows pure air into anything. It's quite powerful as well. Cleaned out my 360 to almost new. Should have seen how much dust was in it. It's an 8 hour drive for access (Grandpa has it..) but I'll see about heading to him for some cleaning. If it happens again, I'll probably just buy a new PSU. HAha, but thanks again everyone

 

[mc-dexter]

seriously... a paint brush is more than enough

 

[Grint2007]

I didn't mention this before, but I did have a bit of a problematic fan. one of the blades on the fan had broken. Gave my finger a right nasty cut, Hehe. But you know how when fans are a bit broken, they shake wildly? Could that have been the culprit? Maybe making the CPU shake a bit too much, pulling it out of the socket?

 

[mc-dexter]

one of the fan blades on the CPU fan? wow, i dare say something like that could be nasty, still dont think it is the cause of your problem though... although i could be wrong maybe.

but seriously why haven't you go that fixed. thats the first tim ei've heard of anything like that being used to cool a CPU, lol.