IMac G5 20" Logic Board, HELP!!

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  • flyguy
    New Member
    • Nov 2011
    • 9
    #1

    IMac G5 20" Logic Board, HELP!!

    Hi all, i have just purchased a sold as faulty, IMac G5 20". It will not boot, but is getting getting power from the PSU because the first LED is lit, when i press the internal power button the second LED lights up momentary and the fans spin for a fraction of a second, then nothing. Now the seller stated it was working then started acting strange, so he opened it up and it had bad caps, so he replaced them, but his soldering skill where not so good, and it didn't help. I will replace the caps again, but i am worried about something i see on the rear side of the board. It looks to me like maybe he somehow he got a little piece of solder bridging across the board (see in pics) and maybe that could be causing the board to short out on boot.

    Please can someone look at the pics and tell me if this is normal or its what a stated.

    Thanks in advance


    http://*************/photo/my-images...369371273.jpg/
    http://*************/photo/my-images...169541273.jpg/
    Tags: None
    • Toasty
      Badcaps Legend
      • Jul 2007
      • 4171
      #2
      Re: IMac G5 20" Logic Board, HELP!!

      Unfortunately, your picture is not clear enough to say one way or the other.

      Without the 2nd light coming on, I'd suspect the PSU before the motherboard. You need 2 on before it will run.
      veritas odium parit

        Comment

        • flyguy
          New Member
          • Nov 2011
          • 9
          #3
          Re: IMac G5 20" Logic Board, HELP!!

          Sorry about the bad picture quality, im suspecting bad caps again maybe, but im no expert. Is there any other way i can test the psu? It also makes a split second sound when the power button is pressed, its a like an electrical spike, best way i can describe it

            Comment

            • Toasty
              Badcaps Legend
              • Jul 2007
              • 4171
              #4
              Re: IMac G5 20" Logic Board, HELP!!

              If it doesn't reach "chime" stage, It's most likely the PSU. No other way to test it than to pull it and have a look inside. Just looking thru the mobo side of its vents usually shows a few "domed" caps.
              veritas odium parit

                Comment

                • flyguy
                  New Member
                  • Nov 2011
                  • 9
                  #5
                  Re: IMac G5 20" Logic Board, HELP!!

                  Ahh ok i will do that

                    Comment

                    • flyguy
                      New Member
                      • Nov 2011
                      • 9
                      #6
                      Re: IMac G5 20" Logic Board, HELP!!

                      All caps look ok inside the PSU, im not sure what to do now

                        Comment

                        • Toasty
                          Badcaps Legend
                          • Jul 2007
                          • 4171
                          #7
                          Re: IMac G5 20" Logic Board, HELP!!

                          Find one of the threads in here with the pinout of the PSU and check for standby 5v and 24v.

                          What model number is the PSU. API#
                          veritas odium parit

                            Comment

                            • flyguy
                              New Member
                              • Nov 2011
                              • 9
                              #8
                              Re: IMac G5 20" Logic Board, HELP!!

                              The model number is API4PC46

                                Comment

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