capacitor replacement help for iMac G5

Discussion in 'PowerPC Macs' started by RedCroissant, Apr 22, 2015.

  1. RedCroissant Suspended

    Joined:
    Aug 13, 2011
    #1
    I have an iMac G5 (17", 1.8GHz, 2GB RAM) with a terrible display and blown caps. Can anyone here recommend the least expensive and best quality (for the least expensive price) replacement capacitors and place to find them so that I can get this $5 iMac investment working properly? Thanks in advance for any assistance!
     
  2. 128keaton macrumors 68020

    128keaton

    Joined:
    Jan 13, 2013
    #2
    I don't know much, but maybe looking at the bad caps and writing the numbers down somewhere (i.e 10uf/100uf) and looking at the size to get a general idea.

    If you want an actual kit, here is something that might work. From pictures and stuff, it seems those two types are the ones to fail, so the amounts there might be a good solution. Happy soldering!
     
  3. mikiotty macrumors 6502

    mikiotty

    Joined:
    Mar 15, 2014
    Location:
    Rome, Italy
    #3
    IIRC, the ones that fail are pretty much only the 1800uF 3.6V (or 6.3? can't remember :p) ones. Any cap with that specifications should work ok.
    Pay attention to the physical size of the cap though. Again IIRC, the max height is 1.5cm.
     
  4. for this macrumors regular

    Joined:
    Nov 18, 2014
    #4
    It is said that the Nichicon caps in the iMac are bad batch: http://en.wikipedia.org/wiki/Nichicon.

    So you can just replace them with the same new caps. There should not be bad ones left in the market by now.
    Fake caps are everywhere. I would avoid buying caps from an unreliable source such as eBay. Digikey and mouser are good places.
     
  5. poiihy, Apr 22, 2015
    Last edited: Apr 22, 2015

    poiihy macrumors 68020

    poiihy

    Joined:
    Aug 22, 2014
    #5
    Fake capacitors?! :eek: oooooooooh now thats interesting I must know more!

    Found this thread:
    http://www.eevblog.com/forum/projects/warning-fake-large-electrolytic-on-ebay-!!/

    HAHAHA capacitor inside a capacitor LOL.
    On the same thread theres a link to a post about fake LEDs on a thread about fake hard drive LOL inside was a hacked 128mb flash drive in a make-shift installation with two nuts and a USB coupling LOL
     
  6. for this macrumors regular

    Joined:
    Nov 18, 2014
    #6
    Hehe, I think that "cap in the cap" is made-up. It would take too much effort to be profitable. Most fake caps are done by relabelling in factory-scale. And there are guides to identify them, like how to spot fake sneakers. :D

    ----------

    In case the iMac's PSU is also broken. There are some info and links in this thread that may be useful.
    http://www.badcaps.net/forum/showthread.php?t=14856

    Normally for a capacitor, the lower ESR (Equivalent Series Resistance) value, the better it is. However for a PSU, a cap with an equivalent ESR to the one it replaces is preferred. Because some PSUs are designed to use the resistance to their advantage.
     
  7. Altemose macrumors G3

    Altemose

    Joined:
    Mar 26, 2013
    Location:
    Elkton, Maryland
    #7
    There are tons of kits on eBay that you can order. Keep in mind to verify the model number with the proper kit as the G5 logic board changed parts and their quantities quite a few times. Since Apple used lead-free solder, you need an extremely hot soldering iron or desoldering tool for this to work. My little RadioShack 25 watt iron just couldn't melt the old solder.
     
  8. cmstuber macrumors newbie

    Joined:
    May 6, 2015
    #8
    I recently replaced all the caps in my 20" ALS G5. I got the caps from Jim Warholic at jimwarholic.com. Decent price and the caps were good. He was kind and threw in some free solder and wick.

    I used a butane soldering iron + a propane torch to help heat my iron. That lead free solder needs a lot of heat! All in all, I think it took me 3 hours to do the job. Take your time and do it right. Don't force anything either.

    My G5 is my main machine so it was definitely worth it for me. It hasn't had a single issue since.
     
  9. archtopshop macrumors regular

    Joined:
    Dec 13, 2011
    #9
    Totally agree. There's allot of good information on that site. I've recapped three, 20 inch Imac G5's so far, and after 15 months they are all still going strong. I am slowly switching my main computer from the FW800 MDD to the Imac G5. I really like it.
     
  10. dyt1983, May 7, 2015
    Last edited: Jun 4, 2015

    dyt1983 macrumors 65816

    Joined:
    May 6, 2014
    Location:
    USA USA USA
    #10
    edit: remove personal identifiable info not relevant to the thread.
     
  11. tigerintank macrumors regular

    Joined:
    Jun 16, 2013
    #11
    I recapped my imacG5 PSU with a kit from Jims site.

    I didn't do the main board as the caps on there were all still flat topped, unlike the PSU.

    It worked for a week or 2 of light use, then the old problems were back. I then bought a cheap PC PSU and re-pinned the cable so I could use that instead. Its been fine ever since - last year or 2 at least.

    I assume that there's something not quite right with the main board and it's stressing the PSU. The PC PSU probably has more 'in reserve' and so works fine.

    Or it could be that something other than caps is damaged on the Apple PSU.

    Either way I'm not fussed as the iMac 'just works' now it has a proper PSU.
     
  12. poiihy macrumors 68020

    poiihy

    Joined:
    Aug 22, 2014
    #12
    "Cheap" PSU? :eek: It's better to get a used but quality PSU than a cheap new one. Cheap ones from china are terrible and can explode in flames.
     
  13. bunnspecial, May 17, 2015
    Last edited: May 17, 2015

    bunnspecial macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #13
    If you want the best protection against cold joints, look for "eutectic solder" which is 63:37 tin:lead. 60:40 tin:lead is also more resistant to cold joints, but a bit harder to work with than 40:60 tin:lead.

    I personally prefer a silver solder. About the only solder I use anymore is 62:36:2 tin:lead:silver. This alloy is eutectic, making it nearly impossible to get a cold joint, and is also stronger than tin:lead solder.

    I actually started using it when I was still doing a lot of repair work on Lionel trains. This is the alloy that was used at the factory-the greater strength was desirable for joints where the wire was expected to flex. I've done so much soldering with that particular alloy that I know its behavior backwards and forwards-that's probably why I still use it even in places where it's not strictly necessary.
     

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