mid-2011 iMac 27 graphics issue: Mac Talk Forum: Digital Photography Review
2 GB Graphics Video Card GPU Upgrade Replacement for Apple iMac Mid-2011 A1312 27 Inch Core i7 3.4 i5 3.1 Desktop Computer, New AMD Radeon HD 6970M HD6970M 2GB MXM Board Repair Parts
Apple opens graphics card replacement program for some mid-2011 iMacs - 9to5Mac
Tarjeta gráfica de 2 GB GPU de repuesto para iMac 27 pulgadas mediados de 2011 A1312 computadora de sobremesa Core i5 3.1 MC814LL/A MC814, AMD Radeon HD 6970M GDDR5 2GB MXM Video
iMac Intel 27" EMC 2374, AMD Radeon HD 4850 Video Card Removal & Repair - iFixit Repair Guide
Reemplazo de la tarjeta gráfica del iMac Intel 27" (Finales 2009 o mediados 2010) - Guía de reparación iFixit
2GB Graphics Video Card HD6970M Replacement, for iMac Mid-2011 27 Inch A1312 Desktop PC Computer Core i5 MAC814LL/A MC814, AMD Mobility Radeon HD 6970M GPU Upgrade MXM Board Repair Parts