Suddenly, my 9300 has started to go quiet when playing back. The sound fades quite quickly and the it stays silent for several minutes. This is the case both when watching livetv via the Humax box and when watching recorded programmes. I've disconnected the PVR from the TV and plugged the aerial (freeview) directly into the TV and everything is fine, so I have concluded that the transmission quality and the TV are OK and the problem lies with the PVR. Anyone got any ideas?