On Mar 30, 2018, at 10:53 AM, Jim Scott wrote: > > In the case of your 2008 iMac, in addition to all of the above, the cooling > fins of the heat sink can be clogged by dust, etc. over time as the air > intake vents directly below the card and heat sink assembly are hoovering up > stuff from the desktop. This leads to overheating and eventual failure of the > BGA. Reflowing the BGA doesn’t work because by the time the problem shows > itself, too many of the microscopic traces inside the chip have been damaged > by arcing. That’s why a more permanent repair involves replacing the chip > with a new one. But new chips are hard if not impossible to find, and my > favorite eBay bad chip repair/replace guy refuses to work on those old iMac > video cards because he can’t guarantee a reflow and he can’t obtain new chips > that will work with the card. > > Been there, done that a number of times. It’s time to ewaste that iMac, in my > experience. > > Jim Scott, Eureka, CA > I have recently fixed a number of these iMacs may sound crazy but it worked for me. It's free and at this point you have nothing to lose.
Take the card off the heat sink and clean all the paste off. Pre heat oven to 390 F (pre heat is important) Place card on 4 small aluminum foil balls at the corners Bake for 7 mins Open door and let board cool don't touch it or move it. When cool reinstall (don't forget to apply new paste). I have also found some with faulty fans so check the fan working before you put it all back together. John Carmonne Yorba Linda CA 92886 USA MacPro 2.66 Quad Nehalem -- You received this message because you are a member of the iMac Group, a group for those using Apple iMacs and eMacs. The list FAQ is at http://lowendmac.com/imac/list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to imaclist@googlegroups.com To leave this group, send email to imaclist+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/imaclist --- You received this message because you are subscribed to the Google Groups "iMac Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to imaclist+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
