Apple iMac 27 inch A1312 2011 Socket LGA1155 Logic Board Motherboard 639-2188 | eBay
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
iMac Mid 2011 27" Upgrade Kit - Real Mac Mods
Apple iMac 27” Mid 2011 A1312 MC813LL/A MC814LL/A Logic Board 820-2828 - NO CPU | eBay
Upgrade iMac Intel Core i3 CPU to Core i7 - iFixit Repair Guide
2010 iMac CPU Upgrade - The whole process - YouTube
Apple iMac Upgrades | SimplyFixIt
HOW TO: Upgrade The CPU from an Intel Core i5 to an Intel Core i7 on a Mid- 2011 21.5inch iMac - YouTube
Teardown of new 21.5-inch iMac surprisingly reveals user-upgradable RAM, modular CPU - 9to5Mac
2011 imac 27" 32GB - final stage of 1TB + 2TB SSD upgrade (replaced HDD & optic drive). Also cleaned out the fans and case. Running 'SSD Fan Control' & 'Macs Fan
Upgrade iMac Intel Core i3 CPU to Core i7 - iFixit Repair Guide