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I have an old Dell Optiplex GX1 that I want to revive. If I plug it in, the power comes on. However, the power switch has no effect (can't turn it on or off, have to unplug it to stop power). I never hear the start up beep or any beeps at all and a signal is never generated for the video output. To be specific, I mean no video signal at all as reported by my LCD monitor, which flashes a "no signal" dialog box when that condition occurs.

CORRECTION: In response to Marcus Chan's comment I did try the 5-second power button hold test and it does shut off the power. In all my trials I neglected that simple test.

I know there are other threads regarding "power on, no boot" conditions but I have some specific questions I would like help with. First, a few anecdotes:

  • I already tried a new CR2302 CMOS battery. Didn't help.
  • I added a processor upgrade kit a long time ago.
  • Although the power button has no effect, the reset button does appear to function. Each time I press it, I can see the CD-ROM read light flash for a bit when the drive powers on.
  • I already tried the test of removing every plug-in board except the VGA, RAM, and processor. Still won't boot.
  • I am using the on-board graphics chipset for video.

I can get a replacement motherboard from eBay really cheap. My main concerns are:

  • Did the motherboard fail?
  • Did the processor fail?
  • Did the BIOS somehow get zapped and that's the real problem?

My main question is, what are the tests/diagnostics I can run to determine which of the three modules above has failed? Any suggested solutions based on you best hypothesis for what is failing are appreciated too.

I am holding on to this ancient system because it is my dedicated music workstation. Anyone who has successfully configured a Microsoft Windows computer to work properly for music recording knows just how hard you have to work to get it to perform properly, especially in regards to interrupt handling and smooth audio recording/playback. In addition, the digitizing hardware is old and I'd rather not upgrade it or the expensive software I use for recording. It works fine and I'd like to revive it.

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Are you using the on board graphics card? I would take out the graphics card and just try using the on board card. –  Corey Feb 3 '13 at 4:54
    
Yes I am using the on-board graphics chipset. –  Robert Oschler Feb 3 '13 at 4:58
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If the power button doesn't turn the computer off, even when pressed for a long time, I'm guessing at the very least either the mobo or power button/input board is dead... –  Marcus Chan Feb 3 '13 at 5:16
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@MarcusChan - I have updated my post since I neglected that basic test. It does indeed power down the system. Please see my correction. –  Robert Oschler Feb 3 '13 at 5:23
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tomshardware.com/reviews/… apparently this model uses a non standard power supply. That makes it a lot more annoying to troubleshoot, since I've seen a PC have the same symptoms due to a bad PSU. I'd forgotten that dell had done this .. wierdness back in the day, and used non standard PSUs. Another system of the same age would be compatible with a modern PSU still –  Journeyman Geek Feb 3 '13 at 7:53
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1 Answer 1

  • Bad RAM should generate beeps.
  • If there's a "clear CMOS" jumper, try using that. I don't think old Dell boards have them, though.
  • If the BIOS went bad you'll want to replace the motherboard. It would probably cost more than a new motherboard to have someone reflash the BIOS manually or replace the flash chip.
  • Check for busted or leaking capacitors on the board. If there are any, have a competent electronics profressional replace them or replace the board.
  • I don't think you'd get as far as you've gotten if the power supply was totally defective. Some Dell PSU's blink amber if the power supply is bad, if yours is one of these, replace it.
  • Take out the CPU, dust out the slot with some canned air, and reseat it.
  • The couple of business-level Dell models I've dealt with will spin the fan at maximum speed if the CPU isn't placed in the slot. If yours is doing this it's probably a bad or incorrectly seated CPU.

Sounds like you've really troubleshooted everything so if none of the above help, I'd first replace the power supply, then the motherboard, and then the CPU if needed.

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