Help please :( PSU failure?

[coolgod]

Hi and thank you for reading my thread.
It means you had an interest of helping me.
I just got almost all of my component delivered today (except for a sata power to 4 pin molex power adapter)
and i put the computer together
phenom ii 955
Asus m4a78t-e mobo
2X 2gb kingston ddr3 ram
1tb Hitachi Deskstar 7K1000.B
1 front case LED fan(those cheap ones, comes with case)
1 side case LED fan(those cheap ones, comes with case)
and one ARCTIC COOLING AF12025 PWM 120mm Case Fan(good ones)
+2 dvd drives and 1 floppy drive.
I was kind of tight on budget and decided to go with the 500w psu on the case.
It had 26a on the 12v line and seeing how i had no graphics card i thought what the hey and decided to try it out. (i'm not much of a gamer, occasionally some counter-strike and empire total war.) i wanted to save enough money to buy dx-11 cards next year and a better psu.
When i put everything together it went fine.
since my dvd drives were all sata power and my adapter still wasn't here, i decided to update the bios.
I finished that and rebooted, i upped the 16xmulti for my 955 to 17x to get 3.4ghz and everything was still fine.
I was monitering my voltage through my bios and everything seemed ok.
they were all pretty stable and all alittle above 3.3v 5v and 12v.
I shut it down for dinner.
After 3 hours i come back and tried starting it only to find a little flashing coming from the side LED fan.
At first the on board led wasn't on, but once i starting to pull on the wires surrounding it would turn on and off depending on the wires.
I decided to test the psu with everything on except the main 24pin atx plug and a wire stuck between the green wire(14 wire) and a ground one. It still powered all those drives,led fans normally.
Did my PSU just fail?
or is it a motherboard issue?
i didn't see any smoke or hear a bang. All i did was go for dinner.

 

[jsc]

What brand of PSU?

First:
Boot problems
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

Second:
Try to verify (as well as you can) that the PSU works. If you have a multimeter, you can do a rough checkout of a PSU using the "paper clip trick". You plug the bare PSU into the wall. Insert a paper clip into the green wire pin and one of the black wire pins beside it. That's how the case power switch works. It applies a ground to the green wire. Turn on the PSU and the fan should spin up. If it doesn't, the PSU is dead.

If you have a multimeter, you can check all the outputs. Yellow wires should be 12 volts, red 5 volts, orange 3.3 volts, blue wire -12 volts, purple wire is the 5 volt standby.

The gray wire is really important. It sends a control signal called something like "PowerOK" from the PSU to the motherboard. It should go from 0 volts to about 5 volts within a half second of pressing the case power switch. If you do not have this signal, your computer will not boot. The tolerances should be +/- 5%. If not, the PSU is bad.

Unfortunately (yes, there's a "gotcha"), passing all the above does not mean that the PSU is good. It's not being tested under any kind of load. But if the fan doesn't turn on, the PSU is dead.

On to the real troubleshooting ...

Disconnect everything from the motherboard except the CPU and HSF, the
two power cables going to the motherboard,and case power switch. Boot. You should hear a series of long single beeps indicating missing memory. Silence here indicates, in probable order, a bad PSU, motherboard, or CPU - or a bad
installation where something is shorting and shutting down the PSU.

To eliminate the possiblility of a bad installation where something is shorting and shutting down the PSU, you will need to pull the motherboard out of the case and reassemble the components on an insulated surface. This is called "breadboarding" - from the 1920's homebrew radio days. I always breadboard a new or recycled build. It lets me test components before I go through the trouble of installing them in a case.

It will look something like this:
http://www.tomshardware.co.uk/forum/page-262730_13_0.html
You can turn on the PC by shorting the two pins that the case power switch goes on.

If you get the long beeps, add a stick of RAM. Boot. The beep pattern should change to one long and two or three short beeps. Silence indicates that the RAM is shorting out the PSU (very rare). Long single beeps indicates that the BIOS does not recognize the presence of the RAM.

If you get the one long and two or three short beeps, test the rest of the RAM. If good, install the video card and any needed power cables and plug in the monitor. If the video card is good, the system should successfully POST (one short beep, usually) and you will see the boot screen and messages.

Note - an inadequate PSU will cause a failure here or any step later.
Note - you do not need drives or a keyboard to successfully POST (generally a single short beep).

If you successfully POST, start plugging in the rest of the components, one at a time.

 

[coolgod]

well i dont actually have a multimeter. What should i do now? I want to swap that psu for an old pretty reliable 350w but i am afraid it might ruin it. Should i try.

 

[coolgod]

I tested it on another older comp
athlonx2 3800+
on board graphics and it still works perfectly so what exactly does this mean?
did my psu fail and not die?
is it my mobo's fault?