42PFL3507H/12 with HTS3551/12 HDMI ARC was working fully OK but then I played radio and USB mp3 files with HTS and TV was going into sleep mode. For unknown reason now TV can't find Amplifier (via ARC + EasyLink) any more - reports that detection failed, will use TV speakers. I tried to switch off/on both HTS and TV but problem exists still. Only way to get TV audio out is via the Coax cable. What shall I do, what is wrong?