no transmision to freesat box?

I go through all the "First time instalation" procedure and no programs are picked up.
I know the arial reception is 100% 'cos I have used a second freesat box to check.
I have tried unpluging the power sorce for a day(as sudgested by the Humax help line)it didn't help.
The machine has been fine for the past 7/8years and then suddenly it wouldn't pick up any stations.any ideas?rgds.J.B.