PC does not start

[nirvanbd]

Hi,
I have a zenith PC powered by intel dual core processor. The pc does not boot and even the BIOS screen does not appear. The fans too do not start. To diagnose the problem, I opened up the PC and tried to power on. The PC fans jerk once and then stop. So I decided to test the power supply. I unplugged all the power cables and tested the no load voltage. All of them were within tolerances except the blue cable (-12V) which registered -10.5V. I am not sure whether this -10.5 voltage is ok for the PC to run.

Then I plugged in all the cables again, powered on the pc and then checked the voltage at one of the spare molex connectors. There was no voltage available at either of the molex cables. So, there is something wrong that happens when the power cable are connected to the motherboard.

In short the voltages are ok when on no load but when all cables are plugged in there is no voltage available(atleast at one of the spare molex connector). Why can this occur. Also what other things can be checked relevant to the above said symptom.

regards,
Nirvan.

 

[alvine]

it sounds like you need a new power supply

 

[nirvanbd]

@alvine,
Thanks for the suggestion. Even I am inclined to think that Power Supply Unit is faulty. But I still have a doubt. Will a faulty motherboard or CPU bring down the voltage (of molex connector that I tested) supplied by the PSU. Just asking this to rule out the faulty motherboard and CPU.

thanks,
Nirvan

 

[nirvanbd]

Hi,

I installed a brand new power supply but the same problem remains. Symptoms are same. The fans jerk once and stop and nothing runs. None of the case LED's light up. Nothing happens.

Any more suggestions for trouble shooting ?

regards,
Nirvan.