I've been bothered with this for a while, usually showing up as failed recordings, When I've checked, I've found that one tuner is showing no signal.

I've faffed about with terminations and cables, assuming that it was a connection problem, and "restored" the missing tuner, but never really been convinced that I've got to the root of the problem.

However, I've now noticed that when a tuner goes AWOL, I can just power cycle, and it returns at full strength.

Anyone got any ideas?

I was having the same problem.
After switching off at the back, for 10 secs, it has not recurred, for a month.

I have noted a couple of times over the past week or so that the HDR has been recording two channels on different transponders (hence using both tuners) and when I have switched it on I have been greeted with a no or bad signal messsage. Channel hopping away and back restores the picture and the signal strength and quality meters are both near 100%.

Checking both recordings showed that they have been successful so there was no loss of signal at all. Weird - I might try a power cycle - its been ages since its had one.

Here's some irony - we were having quite regular power glitches when I was on V13 software but since upgrading to V15 (last December from the Beta site) which fixes the power cut bug we have not had a power cut!