Help finding the busted component (No post/ Fans running)

Hey folks, nice to write something here again.

I'm here to ask for your precious advice.

Few years ago i built my dad a fancy workstation with a 955 BE and Asus Crosshair III Formula.

Yesterday while he was browsing, display went blank and power/reset buttons didn't respond. I cut power from the psu button and tried booting.

No luck, it didn't even post, although all fans are rolling and i can notice a red light on the HD4890 (No power error i think).

I tried pulling out the ram and video card for beeps and it stays the same.

It's been working flawlessly for like 4 years, fine temps and performance.

I hope it's the psu, replacing the mobo would be a hassle, considering it's a fancy one.

On another build a mobo gave up with these same symptoms with the difference that the pc shut down in some seconds, this time i have to cut psu power, so hopefully the problem is on the psu/cpu.

Thanks for reading!

My first thought was PSU. Go with that.

I'm going to try my luck and order to Amazon a Corsair CX750w modular. The actual one is a modular OCZ Modxstreampro so i won't have to mess up the tidy cable management.

My dad needs the pc back to work asap and i can't be bothered to ask relatives or stores for a test psu.

Power and reset buttons don't respond, is that related with the motherboard or the psu?

It's not the psu, i tested it on my other pc and it boots it up.

I've been trying this & that and one curious thing is that when i forgot on my other motherboard to plug the psu to the cpu i got the same red light on the gpu and system would do the same, no post, no display, no beeps, i have to cut power from psu.

Do you think this points at a busted amd 955 and not the mobo?

Sounds like a PSU problem.

Okay if it's not the PSU then you need to start testing the things that would prevent the thing from posting: RAM, CPU, mobo, sometimes even the HDD. Video card wouldn't matter, you'd just wouldn't have a display if that wasn't working.

This is pretty tiring. I've tried the stock amd cooler just in case the CoolerMaster v8 failed and i just ruled it out. It acts the same way if i have the 6 pin cpu power connected or disconnected so i'm pointing at the cpu this time.

I think i'm going to order some cheap FX-6300. Will an AM3+ cpu fit my AM3 board?

@alan_carter: Is this your motherboard? If so, then that is a list of supported CPU's.

@stizzal13: Just what i was looking for, thanks a lot!

I'll have to find some second hand Phenom x6..

So.. it was the PSU. Somehow the failing psu booted up a LGA 775 motherboard, but it couldn't handle the Crosshair III Formula with all the fancy lights, just before ordering a new Phenom II i tried a 750w psu on the Crosshair III and that was it!

Thanks a lot for the help!!!

Ah, I see. Glad it worked out. I know from experience it can be frustrating trying to find your problem.