Hi JohnH77, I think there'll always be one off problems as yours seems to be. In the last couple of weeks, I had two recordings fail due to "lack of power": I am sure that was down to one the short power cuts we enjoy around here.
Viccot, I am now stuck. Tempting as it is to get the drains up and make the changes you suggest, over the weekend the player has settled down and none of the test recordings I made on Sunday failed. It seems to be recording properly right now.
I like the idea that it was pushed off its proper settings by a software update and has taken weeks to automatically reset itself. Next time I have a problem, I'll try your fix. If that doesn't work, I'll try making lots of test recordings: maybe the number of attempts it makes to find the good signal is also relevant.