What is defect? my cpu, motherboard or psu??

[benoitd]

hi,

Just bought some cheap pieces for 150$ but i end up with no POST

after some troubleshooting here's where im at:

With only 24pin plugged in the motherbaord, the fan works. With both 24 and 4pins plugged, just nothing happens.
Since its a cheap board i have no leds or speaker neither does my cheap case :/

PSU: Rosewill ISO-450 tested with the "hotwiring" trick ( http://www.techwarelabs.com/guides/misc_mod/psumod/ )
Motherboard: Foxconn G41M-S (brand new)
CPU: old P4 630 3ghz (Was working number 1 but its been on a shelter for months now)

The problem seems to come with the 4pin in the board. I am wondering what piece of hardware causes this.
Is it possible that a defect 4pin plug from my psu stop my motherboard from atleast turning on?
Is the motherboard doa?
Is the cpu finaly dead?

how can i troubleshoot more without to pay for replacement parts or ripping my other pc apart ?

thanks,

 

[jsc]

Our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

You need a case speaker for troubleshooting.

Once you have a case speaker, the PSU, motherboard, and the CPU; if you boot and you get silence, one of the three is bad. Your only choice is to test by substitution.

 

[SpidersWeb]

What he said.

And he means internal PC speaker (not proper speakers).
Will be cheap, or just pull it from something else. I must have like 10 of them at home.

 

[benoitd]

Tried with another pc's speaker but it doesnt beep at all with or without the 4 pin.
Without the 4 pin cpu connector plugged in the motherboard, atleast the fan starts. When i plug the 4pin just nothin happens.

What next? If i have to go by substitution, what do you recommend to try first?

 

[gomi]

perhaps the psu is at fault? I have yet to have a motherboard completely die on me but then again I usually buy decent mobos and not cheap ones.

 

[SpidersWeb]

Well it'll either be PSU, Motherboard, or failing that the CPU itself.
If you have any spares to swap in/out do that. If you don't have spares, and don't want to take it to a shop (where they will have spares to test with), then only option is to buy one part at a time until the problem is solved.

I normally do the latter, and use it as a chance to upgrade.

It would be great if someone came in with a definate answer, but chances are the options above will be the result.

I'd start with motherboard and/or PSU, and CPU as last resort OR take it to a competent shop.