Switch on problem no processor running

with metal electric tester touch the pins that turn on computer, pins on the side marked with pw

To narrow the problem remove the power supply to the unit then get a small wire to short the green and black wire it is the switch of the power supply, if you do this and the power supply power up, to know that the power supply power up, look at the fan it will turn on.

the problem is in your motherboard..this most cause unregulated flow of power from the source electric..but if the green led is off so its the processor.try to test it with a motherboard tester..or get another board that same spec with the you have,and transfer the processsor if it is working

Bad Power Supply. Weak voltage power rail.

Bestec is a low quality power supply. Used to save the computer manufacturer money.

Also, a Power Supply with a weak voltage power rail will put out enough power to light LED lights, and perhaps spin fans, but not enough power to turn the Processor on, and/or keep it on.

A) ALL the LED lights use less than 1 Watt of power.

B) EACH fan uses 2 to 3 Watts

C) A typical Processor uses 51 to 125 Watts. Depends on what Processor it is.

Replace the Power Supply. Clean the inside of the computer out, with a can of compressed air for computers before installing.

What is the computer manufacturer name, and Model Number. The Model Number is on the back of a desktop computer tower next to the Windows product key, or up on the side of the computer tower.
Post back in a Comment.

Regards,
joecoolvette

Bad Power Supply. Weak voltage power rail.

[There are three main power rails in the SMPS for your desktop computer.
A) The 3.3 Volt power rail
B) The 5 Volt power rail
C) The 12 Volt power rail ]

1) ALL of the LED lights on at once use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts of power.

3) A typical Processor can use 51 to 125 Watts of power.
Just depends on what Processor it.

Remove the Processor, and you will have power to light LED lights, and spin fans.
Of course without a Processor operating, you have No computer.

Replace the Power Supply.

Do you have a KNOWN to be good, Compatible power supply available to use for a test unit?

Need guidance in replacing, or suggestions for Power Supply's to choose from, post In a Comment.

Regards,
joecoolvette

Hello Sir, hi, the wires on your casing are usually labeled, like in the picture below:

the power led green wire goes to the power led + and the white goes to the - . Now the HDD + goes to the HDD + the red wire, power switch can be interchange, same as the reset switch.

Try to reseat the connectors on the mother board.

99% TIME IT IS A FAULTY FAN GOING OUT.

REPLACING THE FAN INSIDE THE POWER SUPPLY WILL RESOLVE THE PROBLEM.

P/S ARE CHEAP, JUST BUY A NEW ONE OOR REPLACE WITH ONE YOU HAVE ON HAND

CANDYMANGANDY

Try to reset the CMOS on the motherboard.

remove all pwoer connector from motherboard and short green and black wire in supply shocket.If supply is run then it is the problem of motherboard.