If you are talking about your phone signal then you most probably have lost your IMEI by downgrading the FW , do a search around this forum you will find many threads along that subject, I think you can regain it by flashing different kernels or ROMS.
IPhone 2G,immaculate, sleeping in the box,bought Dec.2007.
IPhone 4, went to the wife.
Samsung Galaxy Tab 10.1 3G
Samsung Galaxy Note GT-N7000
Galaxy Note II Titanium Grey.