Alba STBX3 losing channels..

[flybynight200000]

I was given one of these models some time ago.
When i installed it, it was fine, found all available channels. The following day after being left in standby it had lost all channels and when i re-scanned it found nothing.
Turned it off at mains left it a while and re-scanned again, everything was found again.
But this cycle repeats itself.
Before i chuck it out has anyone any ideas as to what to do about it.
Many thanks.