Macbook Pro logic board died; Apple wanted $600 for a repair, found a replacement on Ebay for $100.
iFixit guide was invaluable. Opened the machine, removed old logic board, removed heat sinks, put everything back together with a new board, all working, everyone happy. The iFixit super-duper screwdriver kit was a joy to use.
Read the repair guides before you start. Get tools from iFixit.