A Very Strange CPU Issue (AM3)

Well I haven’t been able to solve this problem with my phenom II 965BE processor on my ASUS M4A78-PRO motherboard.

I’ve tried 3 power supplies, 2 graphics cards and 3 different brands of memory, and I cannot get this pc to come out of (S3) standby.

Everything else is working 100% perfect. It will go in to standby but won’t wake up and I have to physically switch off the psu to get the pc back on.

It seems as if C1E isn’t working, I hear this has to be working for the pc to come out of (S3) standby mode, S1 mode works perfect, I’ve been trying to sort this issue for the past week, my motherboard is AM2+ with an AM3 CPU installed, could this be the issue?

Apart from this issue it works perfect, could someone give me any advice as to what the problem could be?

Thank you.

In old days/OSs… this happened a lot due to internal/external connected hw devices/driver issues related with Power Management supported features/commands.
I would try default bios setup, with a minimal hw setup and a fresh OS install in a single spare disk, just for troubleshooting.

I’ll give it a shot see what happens, I really cannot understand why it’s happening lol

Ok tried everything at stock with XP and windows7 it still doesn’t work, only thing it could be at this point is the motherboard as I’ve tried a different cpu and still can’t get it working.