Sky TV puzzle

[Duncer]

I was watching Sky last night before I went to bed, so I must have been getting a signal. However, when I got to bed Mrs Duncer informed me that the Sky in our bedroom wasn't working. We tried switching it off and waiting for five minutes before trying again, as per the instructions, but it kept saying "No signal being received". Several attempts were futile so we gave up and went to sleep.

Today I tried it again and it worked. Any ideas as to what the problem is/was?