[ASMR] Replacement of defective graphics card in Apple iMac 27 "late 2009 and general maintenance

In this new video of almost 40 minutes, we restore a 27 "iMac i5 A1312 from the end of 2009. The world's best-selling personal computer in its different models and screen sizes ... A very comfortable and all-in-one concept It looks good on any worthy desk / office He really appreciated the leap in power made in late 2009 with the newer Intel processors and higher powered graphics cards.
But the iMac from 2009 to 2011 over the years have suffered a lot from the degradation of the solders of the graphics cards, even the case that it is their Achilles heel and their biggest problem. It is not easy to disassemble all the equipment to carry out this operation and they must have nerves of steel and patience, label the cables well so as not to get confused when assembling it again ... Looking a little on eBay, Wallapop or others it is easy to find equipment with this problem, although it is also easy to find compatible graphics to give new life to these great teams. Have you had this same problem? Do you dare to recover one ?.
This unit had already had the original hard drive replaced by a 256MB SSD, but since it is "opened" we are going to carry out a complete maintenance:
Suction cups to remove the protective glass from the LCD
New thermal paste for the processor
Motherboard battery change
Replacing the SSD with a new one with a higher capacity (1TB)
And the renewal of the defective 256MB graphics card for one from a 2011 A1312 computer (fully compatible)
Tools needed:
Clean cotton cloth
Window cleaner or similar
Torx key set
Star screwdriver
Canister of compressed air to remove solid waste
We hope you enjoy the process as we have done, greetings !.