If a PSU is not powerful enough...

If a PSU is not powerful enough, could that cause a CPU to overheat? Or would it make no difference?

I'm just trying to omit possible reasons for a recent upgrade having overheating problems.

*Heatsink was definitely installed correctly (fan working etc.)

*Thermal paste was definitely applied correctly. (done twice same result, cleaned correctly before second application etc.)

*everything was installed correctly in the case.

What I'm thinking is that perhaps the problem is that my case is too small (micro-ATX) and cramped, and I was using the stock heatsink.

I am prepared to buy a new case and better heatsink... but, as I said, I want to omit any other possible reasons first.

Could the PSU cause an overheating problem with the CPU (or any of the other computer components) or not?

It is a 480w PSU.

CPU is Athlon II x4 3.0ghz.(running at 55 degrees idle.)

I used a PSU calculator on a website, and with all my components it recommend a PSU of 420w or something. So my guess is that the PSU is not the problem but the small case.

Do Athlons run much hotter than Intel or something?

Thank you.

Psus have nothing to do with cpu temps unless its on fire. whats your ambient temps and load temps? Cause idle temps dont really mean anything.

Edit: o wait I forgot, It could be your psu blowing hot air on your cpu, but that doesnt have anything to do with wattages.

Psus have nothing to do with cpu temps, whats your ambient temps and load temps? Cause idle temps dont really mean anything.

Azurites

Bios temp was about 55-60 degrees.

Temp under load was about 70-75 I think.

What do you mean by ambient temp, sorry?

I don't have the new CPU installed at the moment so I can't check it again right now.

If you are sure that the PSU has nothing to do with the CPU temperature than I can only conclude that the case is too small for a Athlon II (the Duo core I'm using right now runs at about 30-35 degrees using a stock heatsink.)

Edit: o wait I forgot, It could be your psu blowing hot air on your cpu, but that doesnt have anything to do with wattages.

Azurites

That's a good point. Didn't think of that.

The PSU is located at the top of my current case and it is quite close to the CPU heatsink (not to mention the Disc drive installed close to that also.)

It doesn't sound to me that an Athlon II (x4) CPU is suitable for a Micro-ATX case.