15" rMBP (mid 2012) - screen won't turn on, fans full speed Since yesterday I've been having major issues with my 15" Retina MacBook Pro (mid 2012 model). When I boot it, the screen is black (no backlight: Apple logo doesn't light up). I do hear the startup chime, and it actually does proceed to boot, but the screen stays dark. After a while, I can hear ticks as I adjust the volume, I can adjust the keyboard backlighting, etc. After it boots, the fans stay on at full speed.

I did a PRAM and SMC reset, both to no effect. After lots of fiddling with plugging and unplugging an HDMI cable to an external monitor, I eventually got the screen to turn on. Most things seem functional, besides it being a bit sluggish and the fans still stay at full speed (and there seems to be a LOT of battery drain). I'm using gfxCardStatus and I notice it isn't really able to switch to the discrete GPU anymore.

Does anyone recognize this issue? I suspect it's a hardware issue (broken GPU? broken connection to GPU?), are there any more tests I can do?

I notice in the system report at Graphics/Displays, it only gives me something about the integrated "Intel HD Graphics 4000". Can anyone else with the same model rMBP verify whether this is normal?
Apple has launched MacBook Pro Repair Extension Program for Video Issues which can be found here

Apple has determined that a small percentage of MacBook Pro systems may exhibit distorted video, no video, or unexpected system restarts. These MacBook Pro systems were sold between February 2011 and December 2013.
Apple or an Apple Authorized Service Provider will repair affected MacBook Pro systems, free of charge.