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I bought a computer at the thrift store yesterday.

The computer powered on without any error beeps. Getting it back to the house determined that the CD and hard drive needed to be changed. Put in a populated hard drive to check, the computer turned on and seemed to function. Put in a new CD drive, and just put in a new Hard drive. I plugged it in to check and I noticed that the light for the power supply switch did not come on. But I did notice that the light on the motherboard is lit. and I could not turn the computer on.


  • To help troubleshoot it I unplugged the CD and Hard drive. then re-plugged the power supply and switched it on and off.

  • I re-seated the power connections in addition to the GPU, case buttons, and RAM.

  • Plugged in my 500 watt power supply and the system did not power on.

  • Plugged in new 750 watt power supply and the system did not power on.


  • Motherboard: Digital Home PSW DH deluxe
  • Power Supply: FSP-Group FX700-GLN

Is the Power supply fried somehow?

share|improve this question
only you know if you accidentally unplugged something... and only you can double and triple check all the connections (including Ram, etc) to see what might have been nudged and/or unseated a bit. So... start checking all your connections. – Bon Gart Jun 8 '12 at 21:58
But now that I am thinking of it. Would such a thing as one connection unseated cause such a power supply issue? – Sion Jun 8 '12 at 22:53
@Sion It's possible. Its could be the difference between a Power-On LED and a Power-Good LED. – Ƭᴇcʜιᴇ007 Jun 8 '12 at 23:08
Alright. Re-seated the power connections in addition to the GPU, case buttons, and RAM. Doesn't appear that anything changed. – Sion Jun 9 '12 at 0:15
@sion it could even be a bad power supply switch. Do you have another power supply you can test in the computer? – Bon Gart Jun 9 '12 at 0:24

Grab the manual for the motherboard and you can find the diagram of the pin header layout that i've embedded here

enter image description here

Short out the power and ground pins with a screwdriver with everything else in place. If the system can boot, it will, most likely do so . If it does, the issue is likely with the switch

I'd also check if the speakers are connected - disconnected speakers don't beep.

share|improve this answer
I was going to suggest just using the case reset switch as a temporary power switch (if the case had one), but this is just as good. – Bon Gart Jun 9 '12 at 12:16
Not all the cases i work with have case reset switches - so that didn't cross my mind. I've occationally had to boot up bare motherboards, and tended to favour copper clad 1c coins for that - so i have a switch from a gutted case in case i need to test for switch dodgyness. – Journeyman Geek Jun 9 '12 at 12:18
When I recycle systems for customers (getting rid of their old ones) I strip out the LEDs and reset/power switches from the cases before breaking them down. Almost have a good sized plastic tote worth. – Bon Gart Jun 9 '12 at 12:23
I checked by bypassing the case switch. The power supply did not turn on. Next time I get a chance I plan to check the supply with a multimeter. But for now I suppose that the power supply is dead. – Sion Jun 11 '12 at 2:26
also try connecting the sense and ground connectors on the PSU to see if it powers up that way - this would be the connector connected to a green cable, and the connector connected to a black cable. – Journeyman Geek Jun 11 '12 at 2:28
up vote 0 down vote accepted

I reseated everything again this time including the CPU fan, and it seemed to fix it.

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