I have a PVR 4000T which is about 3 years old. After switching on this morning, every few minutes the output from the box appears to cut out - the screen goes black and the sound cuts off - just for two or three seconds. Then everything goes back to normal for another few minutes before repeating the process. The blue light stays on while the screen goes black, which indicates that it is not a power problem (faulty adaptor etc.) but it's as thought there is a power interruption. I've tried the usual switching off, disconnecting the power cable and restarting, all to no effect. If I bypass the box, the TV works fine through the aerial input so must be a box problem. Incidentally, after the screen blacks out, if I rewind past it and replay the same section, there is no blacking out, so it appears that the box is recording the program ok! Any ideas?