I have an early 2011 MBP 17”. The GPU burned out with exactly the symptoms (blue screen, graphics artifacts, horizontal lines, overheating, crashes, etc) as described by thousands of other MBP users. Apple Store Phoenix's head "genius" feigned ignorance of the faulty GPU issue. I was forced to shell out $322 for the logic board replacement, despite 2 letters to Apple's Tim Cook, but none at Cupertino bothered to reply either time. Apple thinks it has a lock on long term Mac users like me, but they are wrong! The new logic board I bought has exactly the same GPU so I expect it to fail too. The Apple agent at the store assured me Apple had put in a GPU that would not fail like the last one, but that was either a lie or he was speaking out of his arse. Also, the repair center stole my two new Kensington 4 GB DIMMS and replaced them with 2 4GB DIMMS and did not return the originals, which is standard practice. The DIMMS were new and performed perfectly. Both I and the Apple genius ran diagnostics on them just before I handed over my machine and the RAM was fine. I had to demand Apple replace the stolen RAM. Got home and found the new logic board was running even HOTTER than before...fans blowing incessantly whenever I opened a web page with any imbedded video, no matter how small. Bought my own SSD to replace the hard drive, thinking this might solve the heat issue. No improvement. Only after I installed the gfxCardStatus utility and turned off discreet GPU altogether, did I get relief from overheating. Incidentally, all of you who paid the $310 (not including tax) standard repair will only get a 90-day warranty on the supposedly new logic board, not 1 yr. Personally, I don't even trust Apple anymore when they told me the logic board was not a refurb. They already lied to me or gave me incorrect information twice this past encounter.
One further gripe: I bought this MBP in Germany for $3,170. According to the EU Commission, Apple is obliged to honor a standard 2 year warranty on electronics instead of the US's 1 year warranty. Apple routinely flaunts this and I found out when my HD failed 5 days past the 1 yr mark. Apple would not pay. Apple doesn't deserve the right to market in Europe if it flaunts european law. So far, only Italy has taken Apple to court over the 1 yr/2 year warranty issue and Apple lost. Apple now abides by the law, but apparently only in Italy.
Apple is no longer the "Insanely Great" company it was when I bought my first Mac in 1986!