I have a Yamaha AX750 amp, Mission Fs1 speakers and one drunken fool for a friend. I left him alone with the system the other night, I switched on it on last night for the first time since and I'm now getting no sound through the speakers apart from the sub-woofer. So far I've tried the following: Checked the speaker connections Selecting differenet sound inputs (telly, dvd, computer), all have same problem I've done a factory reset on the amp to try and alter any settings he may have changed I plugged in some headphones and am getting sound through them. None of the above had made any difference and I'm stumped for ideas on what to try next to isolate the problem. I'm going to try and get hold of some speakers to try and connect directly to the amp rather than go through the subwoofer after than I'm running out of ideas.