Read all of your posts with interest. My Surface 2 started to not turn on st the end of last year and it would then get extremely hot in the area behind the power switch. After a few hours it would resolve. Called support as was getting close to end of warranty got me to remove some software and reboot. Ok for a few days then would not power up, came up with error message. Keeping up?
Called again, could not resolve online, I'm a student and really needed it working so asked to send it for diagnosis. BEWARE! TAKE PHOTOS OF DEVICE BEFORE SENDING!
I sent it away, it came back badly damaged with a note saying 'intentional damage not covered by warranty'.
I went berserk, called them and they only replaced it when I provided photos proving that it was fine before I packaged it.
LET THIS BE A WARNING FOR ANYONE THAT IS ASKED TO RETURN THEIR DEVICE FOR REPAIR!
Hope it helps someone as it nearly cost me another £5-600 as they had to replace it with a brand new Surface 3 and keyboard.