Dimension 4600 will not power up

   I have a dimension 4600 that when I tried to power it up, all I got was a flashing yellow light on the front panel, but no fans would run. After talking with Dell support, they had me unplug various devices inside the case, I.E. the CD/DVD drives, Floppy drive, etc. (All except the Hard Drive). So they said it had to be a power supply and/or the mother board. I replaced the power supply with a new one from Dell and had the same problem. Figuring it must be the mother board, (as per Dell support), I gave up and bought a new system. I had an old 8100 that I wasn't using much, so I decided to take my hard drive from the "bad" 4600 and hook it to my 8100 to download some files. As soon as I hooked the power supply to the old drive, I got the same problem on the 8100 I had on the 4600! It would not power up and i saw only the yellow flashing light on the front panel and no fanswere running. I disconected the old drive and the 8100 powered up normally. I then installed a new 250gb Seagate drive I had bought as an upgrade for the 8100 into the old 4600 along with the power supply. The 4600 powered up normally.

   Dell says they knew of the hard drive problem but they won't tell you to unplug it during their trouble shooting tips as that is not a "very common problem". I went to this forum for help and everyone with the same problem was told the same thing I was told...replace the power supply and/or the mother board. Sometimes the power supply fixed the problems, other times not, so I thought I would post this message as another alternative. If you are experiencing this same problem, unplug your power supply to the hard drive and turn the power switch on. If your front panel light goes solid green and the fans begin working, replace your hard drive and reboot!

  I am going to find a like hard drive that I removed from the 4600,(a Western Logic, WD400, 40GB), and try to swap the circuit boards to see if I can get the old drive to spin and download.