iMac g5 problems (solved)

Discussion in 'PowerPC Macs' started by Calum2, Jan 4, 2017.

  1. Calum2 macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #1
    So I have recently gotten a broken iMac g5 1.8ghz power PC. I believe it has bad caps though it is quite confusing. It doesnt turn at all, the only sign of life is LED 1 showing green. LED 2 does not flash. Taking out the HDD and replacing the CMOS battery takes no affect. The caps have no signs of being buldged resetting CMOS does nothing. A very faint and short whine (like a beep) can be heard when the cover is off.

    Any help would be greatly appreciated! Sorry for unedited post, it has been sent from my android.
     
  2. rabidz7 macrumors 65816

    rabidz7

    Joined:
    Jun 24, 2012
    Location:
    Ohio
    #2
    Have you checked the capacitors located within the computers AC-DC P.S.U? Have you checked the voltages on the PSU?
     
  3. DeltaMac macrumors G3

    DeltaMac

    Joined:
    Jul 30, 2003
    Location:
    Delaware
    #3
    LED 2 comes on when the iMac is turned on, and the power supply is working properly.

    I would try a different power supply.
    If that doesn't help, then there is a problem with the logic board.
     
  4. Calum2 thread starter macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #4
    I have heard that when the light comes on the PSU can still sometimes be dead. I'll check inside the PSU soon, though I don't have the correct screw driver and it is quite stuck inside the computer.

    As a side note this is the only Mac I have so I have no easily available parts. I could easily buy a capacitor kit off eBay though.
    Thanks for the help
    --- Post Merged, Jan 4, 2017 ---
    Hello I have discovered puffed caps inside the PSU so I will try to replace it or the caps within a few weeks. Does anyone know where I can buy a new PSU?
    Thanks
     
  5. Daniël Oosterhuis macrumors 6502a

    Joined:
    Jan 10, 2016
    #5
    You really won't find a "new" PSU for the iMac G5, at least not in the sense of a brand new, unused one, anywhere. There might be used ones on eBay, but do note that these will develop the same issues over time as yours has. So getting a cap kit and repairing the one you have makes more sense, since it will last longer than any PSU you could get at this point.
     
  6. dustinschings macrumors 6502

    dustinschings

    Joined:
    Sep 3, 2015
    #6
    I have replaced dozens of Caps on the G5 iMacs. They are easy to do if you are okay with a soldering iron. Not too much expertise required. The caps on eBay have worked well for me in the past, and I still have a TON of extras due to never actually replacing ALL the caps, only the bad ones. All the cap kits come with enough to re-cap the whole system (usually).

    If no caps on the logic board are bulging at ALL, you are luck, so keep an eye on them. I think if you replace the ones in the PSU, you will be all set.
     
  7. Calum2 thread starter macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #7
    OK, I'll try to go to a local store and purchase the caps today. It may be a while before they are installed though as I am away from home.
    --- Post Merged, Jan 5, 2017 ---
    Actually, I'll probably just get a cheapie soldering iron there
     
  8. dustinschings macrumors 6502

    dustinschings

    Joined:
    Sep 3, 2015
  9. Calum2 thread starter macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #9
  10. dustinschings macrumors 6502

    dustinschings

    Joined:
    Sep 3, 2015
    #10

    I checked my stash of G5 machine caps, but no luck, sorry. I always get my G5 repair Caps from "The Cap King" Troy Brown thecapking.com (thru eBay, but his site works too). Always has what I need and ships fast.

    Good Luck!
     
  11. Daniël Oosterhuis macrumors 6502a

    Joined:
    Jan 10, 2016
    #11
    I'd again wholeheartedly advice against doing that. Caps really are cheap enough to just go buy new, old ones will already have wear and will have to be replaced much quicker, and I doubt you'd be very happy to do what you're going to do again in the not incredibly distant future. Just go to eBay or another site, and get some nice quality caps. If you want a reliable machine, that little bit of extra money is worth it big time.
     
  12. Calum2 thread starter macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #12
    No need to worry, I have already failed the repair. Burnt the PCB! Oh well, I have two potential sources for a "new" PSU. Hopefully they will be compatible.
     
  13. Calum2 thread starter macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #13
    So its been a while and I have finally fixed my iMac!
    Got a PSU off a Facebook buy/sell page. I installed it a found out that my backlight was broken! Luckily it was just a loose plug. I used it for a bit but it kept on turning off. I thought I had bought a bad PSU but I checked the CPU and it was super hot, it just needed cleaning and new thermal paste. Now it is working fine... except for a high pitched whine when it is on sleep mode, probably a cap that needs replacing, I will replace it in a few years when it dies.

    Anyway! All is working now :)
     
  14. dustinschings macrumors 6502

    dustinschings

    Joined:
    Sep 3, 2015
    #14
    Congrats on the repair and working iMac. As for the squeal, I would replace it before it fails. The caps tend to fail by leaking, and that's not always an easy thing to clean up. Plus, it should be easy to find a swollen cap that is making a noise ;)
     
  15. Calum2 thread starter macrumors member

    Calum2

    Joined:
    Jan 4, 2017
    #15
    True, though I don't want to fail a repair for the 2nd time lol
     
  16. dustinschings macrumors 6502

    dustinschings

    Joined:
    Sep 3, 2015
    #16
    You don't give yourself enough credit. You've fixed it this much already. Now go all in and replace that cap before you get more problems from it ;)
     

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