crwdns2934241:0crwdne2934241:0 mayer

crwdns2934249:0crwdne2934249:0:

An additional resolution to Dan's excellent answer is to get the GPU re-balled.  Here's one service that does that for $75 :  http://www.ebay.com/itm/iMac-VIDEO-CARD-GPU-REBALL-Repair-Service-/261670015894?hash=item3cecbf9396:g:xRMAAOSw-jhUH1dv

crwdns2915684:0crwdne2915684:0:

open