# Dell Dimension 9100 won't start, flashing yellow light



## Octopodes (Aug 14, 2011)

I have a Dimension 9100 running XP that won't turn on "normally", there is only a flashing yellow light when the computer is plugged on. After clearing the CMOS, checking cables etc., I tested the voltages on the psu with a multimeter, using the paperclip test, and everything was where it was supposed to be. I eventually was able to start the computer by shorting the green wire with a black one while the connector was plugged into the motherboard, this caused the computer to start up and continue running after I removed the paperclip. I restarted the computer, and it rebooted correctly. But when I shut it down, and tried to start it again with the power button, it didn’t turn on, the flashing yellow light returned. When I pressed the power button to turn it on that time, the fans and drives started for less than a second, then stopped. I tried starting it again with the paperclip but this time it went to a screen displaying information about my video card and just stayed there. 

I found other people with the same problem who had said that broken USB ports in the front had caused the problem, so I replaced the front i/o panel with a new one with no results. The ports in front were broken, but the ones in back look okay visually. 

I finally found the sticky on psu testing and it passed everything except this part of the continuity test: " Keeping one probe on chasis, use other probe to check the connectors non-black wires are non-zero (if a colored wire reading less than 50 suspect a problem)." Certain wires were reading 20-30 ohms, though I don't know what that means as far as the psu being good or bad goes.

I’m not with the computer right now, but here’s what I remember:
Intel Pentium 4 630 Prescott
ATI Radeon X300
400 or 500 something watt Antec PSU(this original psu was replaced about 18 months ago when the fan inside started making a loud noise)

Edit: There were no diagnostic lights


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## Wrench97 (May 10, 2008)

Blinking yellow on a Dell is either the power supply or motherboard, the blinking yellow is triggered by the motherboard when is does not sense a correct voltage, it can either be because the PSU is failing or the motherboard is failing.
Try another PSU and see if it starts.
XFX or Corsair are about the best supplies for the money currently.


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## Octopodes (Aug 14, 2011)

I tried a working PSU today and it didn't work, does that mean it's definitely the motherboard?


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## Wrench97 (May 10, 2008)

I'd say yes.


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