cheers man, done both, looks like a warranty job.
Sucks man,
Lucky i've got 2 of them though.
It'll still be under 6 months old,
tried holding the power down for a hard reset,
tried video and sound setting in the ps3 menu,
tried moving hdmi ports in the tv,
tried doing a service start (holding down the eject when turning power on at the back)
Tried restoring factory settings (not the format just the restore)