New mobo - no power

[Hodsocks]

Just a quick question for some opinions but I think I know the answer, I had a pc with no power so changed the psu but still no power, checked all connections and tried bypassing the on/off switch but still no power so decided mobo was faulty. I replaced the mobo but still no power, tried another psu and no power, suspect new mobo may be faulty.
I have checked and rechecked all of the connections. the mobo is a socket 478 from Asrock.
Any other suggestions you guys may have would be appreciated.

 

[howard_hopkinso]

I think it`s either a dead mobo or possibly a dead cpu.

I suggest you take the cpu to your local pc repair shop and have them test it. It will only cost a few dollars to have this done.


Regards Howard

 

[blue_dragon]

fans

did any of the fans connected directly to the power supply turn on?

 

[Hodsocks]

When I try to switch on the machine nothing fires up, if I go to check out the psu with my PC/SPS tester the power supply and cpu fans start.

 

[Hodsocks]

A further update, as Howard suggested that it may be a faulty psu I decided to bite the bullet and installed yet another mobo with a new cpu, this time a LGA775 socket to bring it a bit more up to date.
I put it all together switched it on and nothing, so I checked the psu which had failed and it was only showing power on the 5v rail. I then installed another psu, a Thermaltake 480w, and switched it on and again nothing. I checked it all again and have discovered that if I connect the 4 pin 12v plug to the motherboard I get nothing out of it but if I just connect the 20pin ATX the fans fire up and the lights come on, but of course it won't boot any further.
This repair is driving me to distraction, has anyone any suggestions as to what may be going on here? I have a new psu on order which I am hoping will finally resolve the problem but am beginning to wonder if this mobo may be defective.

 

[howard_hopkinso]

I hope the faulty psu hasn`t damaged you new mobo.

If, when you get your new psu you still can`t get it to work, I suspect the mobo is defective.

Regards Howard

 

[Hodsocks]

Thanks Howard we are thinking on the same lines anyway, I am a bit frustrated because the psu that was installed was a new one. I shall be mighty pleased when I have finally repaired this computer cos I have been tearing my hair out with it and when you don't have too much in the first place you can't afford to.