The baking fix (Disscus)

Discussion in 'PowerPC Macs' started by chibiterasu, Dec 1, 2016.

  1. chibiterasu, Dec 1, 2016
    Last edited: Dec 1, 2016

    chibiterasu macrumors 6502

    chibiterasu

    Joined:
    Apr 5, 2012
    Location:
    London, The United Kingdom
    #1
    So I was going to post this last week but things were busy at work and I haven't had time to post but I have been reading and seemed like a good few recent threads had things about reflowing chips. I'm not an expert (I hope more intelligent people on this can comment on this) but reflowing with a oven and/or a heat gun gets banded around sometimes like its a permanent fix for things and really at best in my experience it's only temporary (6 months was the best I got) before having to do it again. It's also a little worring to read when the op says something like they don't know what reflowing is and yet it's persued as the fix as you can easily do more damage to near by caps.

    I think it's also forgotten that it's the solder that's normally the flaw due to it being early lead free solder. In my opinion the only way to solve these problems associated with "just reflow it" is have someone desolder the chip in question, clean up the pads and resolder the chip with a proper BGA array. Now there are circumstances where just reflowing can be useful like in the case of my old PS3 as its a proprietary system turning it on is the only way to recover the data on the hdd.

    Anyway just thought this would be interesting to see what other people's views on this is as we all love our old machines and this kinda thing is only going to become more common over time.
     
  2. gavinstubbs09 macrumors 65816

    gavinstubbs09

    Joined:
    Feb 17, 2013
    Location:
    NorCal boonies ~~~by Reno sorta
    #2
    Reflowing isn't a very good long term fix. Out of 5 boards I've baked only one has lasted to this day.
     
  3. ITguy2016 Suspended

    Joined:
    May 25, 2016
    #3
    I used a heat gun on a dual 2.0GHz system and it lasted exactly 1 day. Once the system cooled down the problem recurred. I didn't have much hope doing so would be a long term solution but I figured why not? The system is useless as is and I couldn't possibly make it any more unusable than it already was. Sadly it didn't work and I ended up giving the system away on CL.
     
  4. Hrududu macrumors 68020

    Hrududu

    Joined:
    Jul 25, 2008
    Location:
    Central US
    #4
    I've done the re-flow fix on several machines, but it certainly hasn't proven to be a long term repair. I've had luck getting a my 17" MBP re-flowed about 3 times and its still working. A 15" MBP worked after 2, but not 3. My 2009 MacBook Air has been re-flowed at least 3 times, but now needs a 4th. The only PPC system I did this with was a 2.1GHz 20" iMac G5. It wasn't mine, so I couldn't guess how long it lasted, but when I last saw it a few months had passed and it was still going.
     
  5. RhianB macrumors 6502

    RhianB

    Joined:
    Sep 3, 2016
    Location:
    Albuquerque, NM USA
    #5
    Same story here. I baked the GPU in my 2006 24" imac about 3 years ago. I also replaced the ram thermal pads and GPU paste. It lasted about 2 years n some change after that. When it croaked the 2nd time, I tried again but it did not fix the problem, so I have an otherwise great condition 24" white imac sitting around because of a crap GPU and new ones still go for stupid $$$.

    Im very leary about buying a refurb because frankly I think that is what they are - broken GPUs that have been reflowed with a heatgun or baked and I don't want to inherit someone else's patched up problem.
     
  6. harrymatic macrumors 6502

    Joined:
    Dec 30, 2013
    Location:
    United Kingdom
    #6
    DIY oven / heatgun reflowing is hardly an accurate science, but I've had nothing but good luck. In all cases I've just done 10 minutes in a preheated 200C oven, on a metal tray supported by tinfoil balls. Assuming it still works, Erik's GeForce 6800 was a card I baked back in 2013 - so that's lasted well.
     
  7. 128keaton, Dec 3, 2016
    Last edited: Dec 4, 2016

    128keaton macrumors 68020

    128keaton

    Joined:
    Jan 13, 2013
    #7
    You could say I've done it before :). My sis's iMac lasted for 1.5 years before I broke down and bought it a proper GPU.
     
  8. chibiterasu thread starter macrumors 6502

    chibiterasu

    Joined:
    Apr 5, 2012
    Location:
    London, The United Kingdom
    #8
    It's interesting to hear everyone's varying degrees of success with their fixes, especially Erik's graphics card lasting for 3 years, it would be interesting to know the use patterns as I always thought heat cycles had a greater effect on these problems.
     
  9. 128keaton macrumors 68020

    128keaton

    Joined:
    Jan 13, 2013
    #9
    If you run it without cooling, it would be self reflowing :)
     
  10. RhianB, Dec 4, 2016
    Last edited: Dec 4, 2016

    RhianB macrumors 6502

    RhianB

    Joined:
    Sep 3, 2016
    Location:
    Albuquerque, NM USA
    #10
    Mine certainly was heat related. For a while before I baked the GPU the first time, for giggles I took the screen out which gets pretty hot on its own and hooked up to an external monitor and the problems seemed to just go away almost entirely (YT video freezing, screen artifacts etc.). When I put it back in, as soon as the screen heated up, the GPU would get all wonky and fail.

    I feel like if and when I do replace the GPU I want to put an exhaust fan in the upper corner. A little fan noise to me is no big deal if it keeps the GPU cooler.
     
  11. Orizence macrumors 6502

    Joined:
    Nov 10, 2014
    #11
    I hate saying this, but a lot of times these BGA chips fail on you isn't because of the solder, its usually a flaw in the underfill used to manufacture. the chip itself. That's why the chips die again right after the fix in a few months, the heat isn't melting the solder, but actually the underfill is getting smoothed out again temporarily. A lot of times when you heat a chip or board like that you aren't even coming close to melting the solder, as the solder used has a pretty high melting point. Im more than happy to be proved wrong, but in a lot of cases the chip itself is simply bad.
     
  12. MacCubed macrumors 68000

    MacCubed

    Joined:
    Apr 26, 2014
    Location:
    Florida
    #12
    You are right about the fact that its almost never the solder joints, the chip is dead majority of the time. The reason that this happens is that the inside of the chip gets messed up due to the heating and cooling of the chip. Once the heat is applied, the inside of the chip will "reset" itself, and last for a short period of time due to the fact that the chip has been worn down.

    Some more info if youre interested (I watched this a long time ago, hopefully my info is still good):
     
  13. Orizence macrumors 6502

    Joined:
    Nov 10, 2014
    #13
    Yep that's pretty much what I meant to say/said. But its not always heating and cooling the chip that hurts it, its the combination of poor materials used during manufacturing and the fact that heat isn't evenly spread and distributed around the dye (because some parts of the chip are used much more than others) so the underfill gets hotter in some places compared to others.
     
  14. ITguy2016 Suspended

    Joined:
    May 25, 2016
    #14
    Whatever the underlying cause of the failure there's enough success cases to warrant at least giving it a try (if someone so chooses it's worth the effort).
     
  15. MacCubed macrumors 68000

    MacCubed

    Joined:
    Apr 26, 2014
    Location:
    Florida
    #15
    That is true, but you can end up damaging other components on the board. So if there are replacement parts available, replacing the dead chip is the best option.
     
  16. ITguy2016 Suspended

    Joined:
    May 25, 2016
    #16
    Since the system is already not functioning there's little reason to be concerned about further damage. Very few people have the parts, tools, and knowledge necessary to replace one of these chips. In my situation it was a last ditch effort to revive something which was non-functioning before writing it off as scrap. If I burned up something else I was no worse off than when I started. IMO it wasn't even worth taking the time to pull the system board out. If I didn't have access to a heat gun I wouldn't have even bothered...just not worth most people's time.
     
  17. havokalien macrumors 6502a

    havokalien

    Joined:
    Apr 27, 2006
    Location:
    Kelso, Wa
    #17
    I have repaired 3 imac 27 inch video cards (2 2009's, 1 2010) by the oven reflow method. 400 degrees at 10 minutes with the edge wrapped around in tinfoil as a stand off. Of the 3 2 are still working as intended, one failed. I also use TGPro for fan control to turn the fans on way sooner to keep the cards cooler than with stock fan control. The slower raising of the temps have allowed them to function for about 1.5 years now.
     

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