New system failing POST

Kencollins

Hi all,

I built a new system a few days ago, and all was working well with the following:

Asrock Killer 990fx motherboard
AMD fx8350 CPU
Asus 630 2gb gfx
Crucial 2x4gb ram
Evo 212 cpu cooler
Corsair 450w PSU

I was using the system this morning any by chance was watching the temp and load stats, it was reading 11 per cent CPU usage, with mobo temp 26 CPU temp 36.

All of a sudden the system turned off. No BSOD, no freezing, just off.

Tried to power on again, nothing.

Flicked the power switch on the PSU off and on, pressed power button and got a one second boot.

had to repeat the PSU power switch and power on to get the one second boot.

Nothing has moved or changed since it was working. I have checked all power and fan connections, and there is nothing shorting the mobo to the case.

I shorted the green lead on the PSU and the fan comes on, so it isn't totally dead.

Could it be the PSU, or am I looking at a dead mobo/cpu?

I got the lot on hardwareversand last week so I dont know what to do now!

Kencollins

Just to add, the system passed an hours worth of prime95 last night, and the CPU package temp did not go above 57 degrees for the duration.

frozenfrozen

Leave it unplugged from the wall completely for about 30 mins, plug it back in and start it up and listen to what beeps you're getting.

In the case that 30 mins break doesn't let it post again, it's shorting somewhere or it's a blown fuse on the cable. In that case, try a new fuse or new kettle lead and see if you can get any life out of it.


I seem to be saying this a lot lately but are you sure you have all of the motherboard standoffs installed? That'd be the most likely way the board would be shorting out.

Also i'd reseat the ram and just generally give all your power connectors and other wires a good check to make sure they're all plugged in.


I presume you were overclocking whatwith running prime95 -- Can you reset your bios and see if that's not letting you boot, although when you're getting no response at all then that's not the first thing you should be checking, but it could be that your voltage is too high/too low for a cold boot.

Kencollins

Hi frozenfrozen,

Thanks for the reply!

I was actually getting some life from the PSU, so I dont think it's a fuse. When I bridged the green wire the PSU, CPU, and Chassis fans started up.

Believe it or not, I am actually missing one stand off. I dropped the lot of them on the kitchen floor when building and one vanished. I left the bottom centre one out and made sure there was clearance after assemble. I will install it tonight anyway as I have some spares now.

I wasn't overclocking at all. The case fans were a bit noisy at full on, so I reduced them to 60 percent in the bios. I was using prime95 to make sure that they maintained a stable temperature under load.

I will check the ram and every connection again. It just seems weird that it decided to die while I was using it this morning. I didng move it or jolt it in any way, it was sitting happily under the desk until I got a blank screen!

Hopefully it is something simple, I will go mad if the motherboard or CPU is toast.

frozenfrozen

Kencollins wrote: »

Hi frozenfrozen,

Thanks for the reply!

I was actually getting some life from the PSU, so I dont think it's a fuse. When I bridged the green wire the PSU, CPU, and Chassis fans started up.

Believe it or not, I am actually missing one stand off. I dropped the lot of them on the kitchen floor when building and one vanished. I left the bottom centre one out and made sure there was clearance after assemble. I will install it tonight anyway as I have some spares now.

I wasn't overclocking at all. The case fans were a bit noisy at full on, so I reduced them to 60 percent in the bios. I was using prime95 to make sure that they maintained a stable temperature under load.

I will check the ram and every connection again. It just seems weird that it decided to die while I was using it this morning. I didng move it or jolt it in any way, it was sitting happily under the desk until I got a blank screen!

Hopefully it is something simple, I will go mad if the motherboard or CPU is toast.

The motherboard standoff strikes again! I hope that's the problem because it'll be an easy fix. The board can take a while to settle into shape and can then make contact with the case and cause the system to not post. Fingers crossed..

Kencollins

It turned out to be something stupid on my part!

I tried a second hand 300w power supply I had lying around, and the system worked perfectly. I assumed it was the power supply causing the issues!

I filled out the RMA form and just before I packed the faulty supply away I decided to check it one more time. It worked perfectly.

I put it back in the PC and it didn't work again. I did some further investigation and found the culprit!!

The power supply has loads of molex and pci-e connections I dont need, so I just had them bundled into the top empty drive bay. At the front of this drive bay is the case USB, audio, and power button interface. They are soldered on to a small PCB, the back of which faces into the top drive bay!

I assume that one of the PSU connections was shorting against these exposed solder legs and causing the PSU to shut down.

I tie wrapped the excess cables to the frame of the case, and the problem is gone.

I feel lucky I didn't ruin the whole thing with something so stupid!