Was playing some 2ch music at 0db at the weekend (via Focal Chorus 726V).... yes it's quite loud but sounded nice and clean, no distortion. All of a sudden the amp shut down and would not restart (just blinking standby LED). Checked speakers which are all still OK and measuring 5 ohms or so. Amp was only playing for about 10 mins so not even that hot, and it's very well ventilated anyway. Eventually managed to get into the diagnostics and "I-protect" was flagged. Further investigation revealed the main power darlingtons on the front left amp channel are short circuit. Not too impressed. I opted for Yamaha as they have a great rep for reliability but to have the main semis go short without warning doesn't seem like great design to me. Anyway, unit is obviously still in warranty but will have to go to a general authorised repair house to be sorted as Yamaha themselves don't have a UK service presence I don't think. It will probably end up at Sontec in Norwich.