[SOLVED] PSU doesn't turn on when connected to motherboard

[deathstroke173]

Hello, I have a old pc that didn't want to turn on (jumping the power pins didn't work). I tested the PSU using the paperclip test and it turned on so I tried the PSU on another motherboard that I know is working and still didn't turn on. I tested the PSU voltages and they are within limits. Both motherboards work when tested with another PSU. What can cause the PSU to turn on when using paperclip method but it doesn't turn on when connected to the motherboard ? The problem is definitely with the PSU I just want to know if it can be something fixable like a faulty capacitor, maybe someone had a similar problem.

CPU: Intel Core 2 Duo E8400
Motherboard: Gigabyte GA-EX38-DS4
Ram: PQI2x1gb
HDD: WD 500gb
GPU: Nvidia gt630
PSU: CHIEFTEC CFT-750-14C - around 12 years

 

[Lutfij]

Please list the specs to your build like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:

As for the PSU, please include the age of the unit, apart from it's make and model.

 

[Dark Lord of Tech]

Paper Clip test only shows that it produces some power. Doesn't prove the power supply is viable.