I might be talking rubbish,but if it's a Vestel chassis,the one with no sound go to freeview,first time install(retune) & sound should return.Only if set is Vestel around 4yrs old.Don't know about the other one,might be worth checking CHS ltd they do a lot of pre-programmed eeproms these day's.
The sound one by the way even if set is used with Sky/Virgin box still do the freeview thing,it does work.