mine keeps saying code 11 protection.
A while back I read a thread on audioasylum (I think) about the 3000es - the early models did not have the plastic 'seal' on the back and many people had their unit lock up because a stray strand of speaker wire touched the unit and it shorted. Apparantly when this happened the unit locked up and said "code 11 protection" and had to be sent to Sony to be fixed.
Maybe the 4ohm speakers caused a similar situation...
From what I read it had to go to Sony to be fixed, but don't quote me on it.
Mine has to go to Sony to repair the hiss issue....