Can PSU Be Faulty Even If It Can Be Jumpstarted?

[MaxArk]

I am having major problems with my system (doesn't start). I'm trying to diagnose whether the problem is with the PSU, motherboard, or CPU.

I've tried to diagnose with the breadboard test (all components removed except 1 stick of RAM, CPU and cooler) and no go. CoolerMaster SilentPro M1000 watt PSU fan didn't fire up, a solid red LED on the motherboard only.

I used the paperclip test on the PSU. With the papeclip in place, the PSU fan fired up. If that enough to rule out the PSU as the culprit, or could it still be the cause of my big problem?

 

[InvalidError]

The "paperclip" test only tells you that the PWM controller can be turned on.

This tells you absolutely nothing about the quality of the power (voltage accuracy and steadiness) coming out of it at whatever load your system puts on it. The PSU may turn off but DC outputs may be too far out of spec or too noisy for reliable system operation.