The replacement board that I’ve got has not got a grey plastic flip down ribbon cable retainer! How do I swap one from my old board?
Apple had a replacement service for late 2011 15inch MBPs which cured a mysterious fault which rendered it un-usable. I had mine fixed at a Genius Bar but my mate who also bought one has missed the program and has a completely dead MBP. Am I right in assuming that following your procedure above and using one of your logic boards would fix this?