Computer won't start (Nothing happens)

thebosno

Distinguished
May 11, 2016
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18,515
I just came home this morning and my desktop doesn't turn on. Nothing happens. I checked and the motherboard light is on. I did the paper clip trick and the fan of the PSU turns on I also removed the CMOS battery and put it back in. I've had the same components for 2 years and just now randomly it won't turn on, so I don't think it has anything to do with the connections. What is the most likely cause. Could it still be the PSU even though the paper clip trick didn't suggest it?

This is so frustrating. I will be happy to answer any other questions pertinent.
 
Solution
A ha .

As you know Psu`s have circuit protection built into them.

Most have.

OVP Over voltage protection.
UVP Under voltage protection.
SCP Short circuit protection.
OCP Over current protection
OTP Over tempreture protection

And the power Good circuit.

If at any point where the Psu is powered, or is a rest state.
Any spike or feed from the mains will trigger the circuit protection of the power supply.

The state is then remembered until the protection circuit is reset.
This is to prevent the system from being powered up in case damage may be caused to the system.

The protection circuits as much as from the mains side and the Psu it`s self are also triggered in such a case as the motherboard developed an electrical fault such...
A ha .

As you know Psu`s have circuit protection built into them.

Most have.

OVP Over voltage protection.
UVP Under voltage protection.
SCP Short circuit protection.
OCP Over current protection
OTP Over tempreture protection

And the power Good circuit.

If at any point where the Psu is powered, or is a rest state.
Any spike or feed from the mains will trigger the circuit protection of the power supply.

The state is then remembered until the protection circuit is reset.
This is to prevent the system from being powered up in case damage may be caused to the system.

The protection circuits as much as from the mains side and the Psu it`s self are also triggered in such a case as the motherboard developed an electrical fault such as a short circuit.
A component on the motherboard that is broken or fails to work will trigger the short circuit protection of the Psu to prevent fire ect.

Doing the paper clip test by removing the main 24 pin 12v Atx power block, only confirms power is good.
But it does not confirm that a protection circuit of the Psu has been triggered.

So in order to reset the protection circuits. you must first switch off the rocker switch of the power supply unit found on it.

Turn the wall switch off at the wall socket.
And remove the plug from the wall socket.

After about ten seconds plug the plug it`s self back into the wall socket.
Turn the switch on at the socket. and then the rocker switch on the back of the Psu back to the original state.
Then press the power button on your system.

If the protection circuits were the problem then it should fully power the system on.

If not then it points to a problem with the motherboard it`s self.
Or a component connected to it via one of the interfaces at fault.

Examples Bad Pci-e graphics card or a memory stick that no longer works.
It will be treated as a short circuit by the power supply.
And will not power the system up until the non working part is removed from the motherboard.
 
Solution