Still loving the iMac...But why in the name of the lord???

Discussion in 'PowerPC Macs' started by patriciooholegu, Aug 21, 2015.

  1. patriciooholegu macrumors member

    Joined:
    May 18, 2014
    #1
    So, a few days back i saw, again, an internet auction from a guy sealing his old iMac G5 Als 20 inch 2.0ghz PowerPc, with everything, like keyboard and mouse. Even the original box.
    The thin was, claims the add, not turningh on the screen.
    So i bought it...for us$50.
    Just before it arrived home, i started to collecting 1800uf capacitors to get my hands dirty on that logic board (I have done it before with very good endings)
    But wen it arrived, i opened up, and my surprise was big: All Caps wore just fine. Perfect. Even the entire machine was completly clean, inside and out.
    So powered up and two beeps came. 3 seconds lather the fans became completly crazy.
    Yep. Ram.
    Replaced and the same.
    Removed Pram Battery and checking, it gives my 1.5 volts (Out of 3.2).
    Replaced with proper one and powered up...
    The dam thing started to boot!!
    To good to be true?
    Oh yes: Wen it heat the desktop, it pixelated.
    But it worked.
    So after a few days i have came to the conclusion that this thing need REBALLING:

    https://en.wikipedia.org/wiki/Rework_(electronics)

    The question to you all is (Based on experience) should a reballing be Ok, or is it the Graphic Chip gone bad-Not the soldering balls-the one with the problem?

    No need for pictures to be taken here: This as being a very often common problem in this old iMacs (Search for iMac G5 Pixelated screen).

    Thanks for any suggestion.
    Sorry about my English.
     
  2. MacCubed macrumors 68000

    MacCubed

    Joined:
    Apr 26, 2014
    Location:
    Florida
    #2
    It could be both, try a reflow first, if that cures it, the chip is fine and just needs a reball. If not a new chip is needed
     
  3. patriciooholegu thread starter macrumors member

    Joined:
    May 18, 2014
    #3
    Thanks for answering.
    Just did that today. It took me 1 hour to disassemble and about 2 more to put everything together again.
    Now is working just fine after a pretty "Homemade" Heat gun - no flux reflow (I do not recomend this. But the Reballing machine i have access now is not usable for personall things).
    Something i notice is that cpu idle temps before reflowing was almost double then after...
     

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  4. MacCubed macrumors 68000

    MacCubed

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    #4
    Glad it worked out! I still recommend a reball, it ensures that the solder wont break again that easily
     
  5. gavinstubbs09 macrumors 65816

    gavinstubbs09

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    NorCal boonies ~~~by Reno sorta
    #5
    Interesting that the ALS needed a reflow. My iSight G5 needed it twice to make it usable for a month! Which it died after that point and I moved on to never want another iMac G5 again...
     
  6. mikiotty macrumors 6502

    mikiotty

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    Mar 15, 2014
    Location:
    Rome, Italy
    #6
    I actually have an iSight 19" G5 iMac and I already reflowed it twice... I suspect it will soon die :(
     
  7. patriciooholegu thread starter macrumors member

    Joined:
    May 18, 2014
    #7
    The fact that caps wore just fine, mint and everithing completly clean, and factory thermal paste and thermal pads, make my think that:
    *This iMac presented the problem from the very begining.
    *No reflow or reballing atempt since today
    *I´m lucky this day. (Writing this from the very same iMac). Should i go to the Casino...
    *In case of future failures, maybe should i try to "Hackintosh" this one with a Nuc (Painfully slow this thing. The guys from Apple did a great job making it obsolet):

    http://www.tonymacx86.com/imac-mods/148974-ersterhernds-imac-g5-20-inch-a1076-project.html
     
  8. MacCubed macrumors 68000

    MacCubed

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    Florida
    #8
    I still like keeping my PPC's original, do you have access to a reballing station?
     
  9. patriciooholegu thread starter macrumors member

    Joined:
    May 18, 2014
    #9
    I have access to one, since it is my job. But due to one of my own rules "Do not use the reballing station to play, test, or Try-to-make-this-toast-to-see-what-happens... im not able to make the reballing unless i pay for it.To my boss...
     
  10. MacCubed macrumors 68000

    MacCubed

    Joined:
    Apr 26, 2014
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    Florida
    #10
    Then it may be cheaper if labor isn't included, ask him how much it would cost lol. It would cure the graphics issue for good and you'd have a nice working iMac
     
  11. 128keaton macrumors 68020

    128keaton

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    Jan 13, 2013
  12. patriciooholegu thread starter macrumors member

    Joined:
    May 18, 2014
    #12
    So a few word, a few days after:
    The machine is working great. I´m using things hard with confidence and there is something wort to mention:
    The day a made the DIY reflow, i notice that two caps soldering points seemed to be noticeable wrong. They looked like certain LCD monitor with the problem called "Cold Joints" and a litlle bit of Flux on them...and i resoldered on the fly.

    This fact was so under estimated for my that didnt think about it until a few days back...

    Let my explain: The diy reflow, if you ask my, should not be work for more than two days...
    I know because in my field of work, YOU KNOW thats not the proper way to fix the thing.

    So thinking about the entire situation now i´m reaching the conclution that this was resoldering fix, and not the reflow...
    The picture is not mine, just took it from google.
    Sorry about my English.
     

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