Hi i have the bush a642n which works fine nut the remote does not work on the tv . when the tv is on standby and the red led is on the remote has no effect and when the tv is on via the buttons on the side and the blue led is on when you try to use the remote the led flashes so it senses the remote is working but the tv does not change. any ideas please if it needs a new part would you know where i could get it many thanks Simon