Computer not turning on

[yellowbadger52]

Ok so my friend has a computer that another person built and hes being using it for about 4 months. Today it would not turn on at all. So i went over and tried to start it and it wouldnt and as i inspected it i only found one problem. The 4-pin connecter that is supposed to be plugged into the motherboard with the 20-pin connecter was not plugged in. So i plugged it in and tried to boot it and it wouldnt. So my question is Because hes used it for about 4 months without that 4-pin connecter plugged in is it possible it fried the motherboard or cpu??

 

[nossr50]

I don't think it's possible to damage parts with less electricity. It could be a coincidence that the 4-pin wasn't plugged in when you inspected it. If nothing happens at all when you hit power, the front panel could have been knocked loose, or the cpu may have been incorrectly installed. If I was a betting man I would say his power supply probably lost wattage during the 4 months and cannot boot up anymore, but that would mean that it was the bare minimum in the first place. But sometimes the simplest answers are correct.

 

[Frank Booth]

The 4 pin next to the CPU, or he has a 4 pin that goes next to the main cable?

You have to troubleshoot the sucker. Disconnect all the power supply cables. Plug in the power supply and see if the fan goes on. Some might need the main cable - 24 pin or so - be plugged in to be turned on by the computer switch. First step is are you getting power?

If you are then next step. Do you hear beeps, any kind of noise. Smell the board. You can smell burned capacitors or resistors, which is most likely what can go wrong if it fried. If you tough fixing something is all high tech, not exactly true. The nose is very important, i think the most underestimated sense. !lol I will leave it at that for now.

 

[-nocturne=-]

Some systems will run fine without the 4pin connected, but most will give you a BIOS warning upon bootup if it's going to be a problem...

My advice... leave the BIOS battery out for a few hours, tear all the cabling out, and put it back together... most often, that'll get it back to booting again.

 

[nossr50]

I wouldn't take it out for a few hours, try for about 15 minutes instead.

 

[yellowbadger52]

Ok i can do that. I actually posted a thread on overclock.net and they said you cant really damage it. Its the plug thats supposed to connect with the 20-pin connector. the computer wont boot up at all. It shouldnt have lost voltage because this pc is not even close to a powerhog. Its rated as a 480watt psu and this pc has a cheap proc, 1 gig of ram a dvd drive and 1 hdd so it cant be it was using too much. Ill try all that stuff and see if that works and ill let you all know what happens. thanks for the help everyone

 

[Josey Wales]

I will chime in, 4 pin connector if it went to power the cpu is impossible to not have connected and have the computer work. To be serious you need to say what the computer is and has. My guess from what I've seen you write is, if the power isn't even spinning fans, you got a bum power supply. Doesn't matter the wattage, if it's older and cheap and no fans spin or nothing happens at all, double check connections and all but you the power supply died. If it starts for a second and shuts off, check and reseat the heatsink because you're probably overheating the cpu. If it goes to load OS and can't, run memtest because memory is your best bet.

My bet is psu from what you wrote.

 

[subtle_turtle]

I'm going to say PSU as well. A blown fuse can happen for a lot of different reasons, and sometimes for seemingly no reason at all. It'd certainly be the first thing to look into, before worrying about the mobo.

 

[yellowbadger52]

Ok well thanks everyone. I think its the psu cuz it wont turn on at all and ive fiddle with the connections. I hit th eswitch to turn it on and nothing happens. The case they have is a really cheap case with a cheap psu. So im thinking maybe either the switch on the case went bad or the psu died but im leaning more to the second one. Im gonna have to check it out tommorrow maybe and make a final decision.

 

[Sharp67]

Had the same prob man and i replaced the PSU and it runs like a charm (other than the 2.5 V rail thing)