Hi, here's the problem. On Sunday was watching a film and noticed no sub moments. Was hoping it was just a fuse but after some checking it's looking like the amp output. Firstly I checked the fuse at the power socket as the ms309 is famous for them blowing even though the power on led was lit up green and when switching from off to on you can hear the internal amp clicking on. I then removed the sub cable from the amp switched the sub on and tapped my thumb on the amp end of the cable and you can hear the sub thumping slightly thus telling me the mark grant sub cable and the sub are working ok. Now because its a mordaunt short sub and they have previous for sub issue's I then removed the back from the sub and checked the two internal fuse's and both check out ok. I then connected a phono feed from my pc to the L+R line in on the sub and played music which the sub did output even though it sounded terrible it worked. So I am now thinking that the sub and the cable have been tested and are both working. I then look to the amp which was only purchased in January played a source through the amp with sub moments and on the display the LFE indicator is displaying that the amp is outputting to the sub channel but there's no sound from the sub. I then ran the MCACC thinking that this is a set up feature that regardless of any current setting's when ran, it will determine what speaker's are connected to the system and its not picking up a connected sub-woofer which lead's me to think that the sub output has failed. Sorry for the long winded explanation but I wanted to cover everything I have tried and am wondering if after reading this would you agree I am on the right track, is there anything else i should try before contacting Richer Sound's, am I missing something. Any help suggestions appreciated. Moderator's i was not sure where to put this post as it's both amp and sub relevant please move if required.