Computer won't power up

ZachE84

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Aug 21, 2003
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Hello, I have just bought parts to build a new computer. I have done this before, so I know what parts go to together, so it can't be a compatability problem.

Anyways, the PC won't even power on, the CPU fan doesn't even come on! Only things plugged in are the CPU, CPU fan, and the power switch. So obviously, it has to be the motherboard? The CPU is installed correctly. The front panel connections are plugged in rgiht also.

One question, If I installed the CPU wrong, powered up, would it fry the mobo?

Any ideas....i'm totally lost! Thanks a lot.
 
G

Guest

Guest
Im pretty sure that the computer would have booted at least once and then shutdown all of a sudden. You can also usually tell if component are fried by the smell.
Anyway, unplug everything remove the cpu put it back with the HSF make sure the PWR button is on the right pins and that you turned the switch behind the case =) heh.
Since im sure you already done that, the only way to make sure is to test the Motherboard in another case and your case with another motherboard.
Like this you can isolate it to the motherboard or to the PSU. As I said smell both of them, fried electronics have a really special odor...
Good luck
 

Flinx

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For some of the newer Mobo's there are additional 4 pin power connnector to attach i.e. P4 ready.

Some AMD boards have this connection too.

<A HREF="http://www.motherboardrepair.com/index.php?sec=images" target="_new"> bad caps </A>

A short on the motherboard, did u lose a screw and it is jammed underneath. U used a support improperly? Something like that

The loving are the daring!<P ID="edit"><FONT SIZE=-1><EM>Edited by Flinx on 08/20/03 09:25 PM.</EM></FONT></P>
 

ZachE84

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Aug 21, 2003
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Thanks for your reply.

Well, thats a good idea. I'll take the Mobo out and put it back in.

Also, sometimes when I try to power it on, my optical mouse gets power, and the light in it stays on forever unless i cut the power to the computer. Also, about 1/10 times I try to power on the computer, one of the case fans turns on then right off again....weird.

Thanks.
 

rcj187

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ok just thought id check. you have the jumpers set right i assume? fan plugged into the cpu fan plug? is there a jumper on your mobo to clear the bios? is that in the right position? they normally ship in the clear position in which case it wont boot.
power switch connected correctly?
ahha just read one of your posts sayint that sometimes the fans spin then stop? do you have the hsf on correctly orientated? are you using any thermalcompound? sounds like it may be overheating and cutting off? if you have a jumper to switch between 133 and 166 fsb make sure thats set right too..
basically strip the whole thing back down check EVERY jumper in the manual. take the mobo out the case take the hsf off the cpu remove cpu from socket.strip down and rebuild it... check all cables and connections etc etc
make sure you dont have any support posts grounding out the mobo
psu switched on..some have an on/off switch on the psu itself?
 

ZachE84

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Aug 21, 2003
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rcj187!!! You're the man, i took ym mobo out, took out the cpu and cpu fan, replaced the mobo in without any screw this time, its loose at the moment, put the cpu + fan in, and it powered up! Thanks a lot, only took 3 minutes, but i've spent 3 days, haha.

THANKS!!!!
 

Crashman

Polypheme
Former Staff
It sounds like you've had a grounded board. This is usually caused by a mouning post touching a circuit on the back of the board. You need to find the offending mounting post and remove it. EVERY mounting post should line up with a hole in the board, otherwise, you'll be back to square 1.

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