iMac G5 diagnostic lights?

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  • ub6ib969
    Senior Member
    • Jul 2010
    • 198
    #1

    iMac G5 diagnostic lights?

    I Have a few questions about my 17" imac 1.8ghz G5. I was receiving a chime but only diagnostic lights 1 and 3 appeared lit. I am receiving nothing on screen. I was told to use this method to diagnosis mainboard caps. I found the transistor that controls the led of diagnostic light 3, using my multimeter switch to OHM resistance, the ground on the transistor and the positive on the cap, I tested each cap on the board and replaced whatever one diminished the green light. Now the machine doesn't chime but does start up only showing only diagnostic light 1! The PSU is tested and working great with other machines so that is not the problem. Any help would be great!
    Tags: None
    • Toasty
      Badcaps Legend
      • Jul 2007
      • 4171
      #2
      Re: iMac G5 diagnostic lights?

      #2 light never came on?

      https://www.badcaps.net/forum/showthread.php?t=7124

      Post #10
      veritas odium parit

        Comment

        • ub6ib969
          Senior Member
          • Jul 2010
          • 198
          #3
          Re: iMac G5 diagnostic lights?

          UPDATE:
          Light #2 never came on however The computer now works fine. I replaced 2 1800uf 6.3v caps on the left side were the (5) 1000uf 16v are grouped and now it shows me a screen. I installed Leopard and everything is working great, but light 2 is still not on!?

          -Thanks again Toasty.

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