Computer won't boot. Blank screen, No beeps, fans spinning full speed

[manbungo996]

Hello
My computer had previous issues with not turning on from the first try, but that got resolved by switching a power supply with 4 pin connector with an 8 pin connector (the MB supports 8 pin).
Since then it worked fine, however it suddenly wouldn't turn on at all. The screen is black, monitor doesn't respond, the MB speaker makes no beeps, but the case, processor and GPU fans spin at full speed.
I have tried resetting and replacing the CMOS battery; removing and replacing the RAM memories; and replacing the GPU. Also I tried 2 other working power supplies. All the mentioned components were tested on another computer and they work fine.
I have also tried switching to another power outlet, even other cables, but the problem still persists.
I suspect that this is either an issue with the processor or the motherboard itself, but I can't test those because it's an AM3+ socket, and I don't have an AM3+ processor laying around to test on the motherboard, and I don't have another AM3+ socket motherboard to test the processor on.
What other problem could it be, or if it is one of these, which is it and what should I do next?

Thanks.

 

[Digerati]

the MB speaker makes no beeps

Did it used to? When all is good, if there is a "system" speaker (and it is enabled in the BIOS Setup Menu), you should hear a single short beep indicating a successful POST.

Also I tried 2 other working power supplies.

It seems you have eliminated everything you can now, but the case. If me, I would pull everything out of the case and set it up on a bare wood cutting board, or plain sheet of cardboard. Note the two pins where the two wires from the front panel power button connect to the motherboard.

Once set up on the breadboard, carefully, and with a steady hand, momentarily short those two pins with a flat tip screwdriver. The computer should boot. If not, and since you tried different supplies, then you are right and it most likely is the board, or the CPU. And without a spare compatible CPU, or motherboard, there really is no way of telling which is bad. You may have to take it to a shop and have them isolate the problem as they likely have a stash of spare CPUs.

 

[manbungo996]

I tried to set it up in another case as well before, same result.

However, today I just tried turning it on again, without changing anything, and now there is a different problem. It just begins spinning everything for a couple of seconds and shuts down, and it won't let me turn it on again without switching the power supply off and on again. I tried three power supplies, which all work properly on other PC's. I again tried to remove everything except the processor, the 8 and 24 pin connections, but the same goes on, which is different from what I described previously. Is this pointing that it's more likely a motherboard issue?

 

[Digerati]

Is this pointing that it's more likely a motherboard issue?

That's my thought.