Problem starting up PC

Had my pc for over a year now but this last week i have been having a problem getting it to turn on. when i hit the power button it comes on for 1-2 seconds and immediately turns back off again, after a few tries it does boot up and says "Please reset CPU or memory frequency in CMOS setup" and the choice F1 to continue of DEL to enter BIOS. pressing F1 it boots up and when its running everything seems to be running like ususual but i have noticed a crackling noise that sounds like it is comming from the PSU im not 100%. I Dont want to use it when i have to keep forcing it to turn on incase i damage the hardware. Any ideas whats causing this problem?

A faulty PSU could easily be responsible for your problem, specially since you are hearing "a crackling noise". It could also seriously damage PC components including the CPU. I would suggest you test voltages and stop using your PC till you confirm this problem.

what would be the best way to test the voltages?

A typical multimeter wouldn't detect spikes. An oscilloscope would.
I'd definitely determine if the "crackling" was coming from the PSU. You could also try running the PSU with output DC connectors unplugged. Be mindful of dangerous live 110/240v.

If it is coming from the PSU you could get it repaired depending on cost. If it was mine I probably just replace it.