Problem with my pc

[bizzare6543]

My PC was fine on Friday morning, turned it off and came back later and tried to turn it on. It wouldn't POST the first time, but was fine the second, but I noticed my BRAND new HDD was clicking tried it in a different PC, which I know works, so I'm going to need to RMA that.

Took the HDD out, but I was still getting the same problem with random POSTing but obviously without the HDD clicking. Since then I've tried a few things, 1 stick of RAM, the other stick of RAM, a different motherboard and a different PSU. The only thing is I'm not entirely sure if the other motherboard I tried even works, but with that motherboard wouldn't even POST.

Only thing that's stayed constant which I've been unable to test is the CPU, does it sound like the CPU has finally given up? Or could it be my motherboard or something else.

Any ideas on which is more likely, or if you think it may be another component.

Thanks for any help you can give me.

 

[bizzare6543]

OK I'll try to word it more clearly.

The actual problem is that my PC suddenly only POSTSs occasionally. When it does POST I can get to the BIOS and everything is fine, but when it doesn't, all the fans power up and I don't even get any beeps, and the speaker is plugged up. I've tried everything you've suggested but unfortunately I can't try a different CPU, but I can try a different GPU if it's worth trying?