Chosen Solution
Hi there. I am Wika, from Bali. My iMac (i7 3.4 GHz model) just had the VGA issue. The problem started with the laggy and skipped mouse cursor. Additionally, the display was sometimes flickering. I though it was due to the HDD (or the RAM compatibility) as it was quite old machine. Then, I replaced the HDD with an SSD. It did work smoothly for a couple day until the flickers appeared on a regular basis and the booting was stuck. After searching on the internet, I convinced that it is due to the VGA fault. I found ‘the baking method - by heating the VGA in the oven (200 degrees about 8-10 minutes)’for 2010-2011 model, but not for this model. I would like to know how to open the VGA and what is the best way to repair it. Is the baking method will work for this model? I found only one video on youtube repairing this (the slim) model. However, the movie quality, the content and the way his recording the video was very low :(. Sorry for being honest :( Please help if you have found the solution. Thank you very much.
Sadly the 2011 logic board is the last model with a removable GPU sub assembly board. Apple altered the design so the GPU chip is now mounted directly on the logic board on 2012 and onward.
There is little you can do to fix this as heating the full logic board is risky! And in truth, really won’t fix the underlying issue as the issue you are facing is deeper in the chip. Its time for a new logic board - Sorry ;-{
