DW800 strange

Hi guys
Most of my channels now say no signal or a black screen. I live in north london and unless i am wrong we are not due for a upgrade yet. I have done a system restore and deleated channels but when i try to do a scan i have a strong signal but no channels are being stored.
Any idea guys?
Cheers in adavnce

Thought most of London was already N3?

Have you recieved a ned card from vm yet - if you subscribe that is?
You could try a factory reset and scan again but I suspect you may have migrated to N3.