Possible RCA converter box problem



I have a RCA box serving a Sony analog TV using an attic antenna with an amplifier. After a month of the TV, antenna amplifier, and box being disconnected from the power supply/surge protector, the surge protector being turned off, and the incoming coax cable (from the amplifier) being disconnected the system will not work after re-connection. The TV displays wavy lines that change somewhat as the channel selector is cycled, The audio is a hiss that changes volume with the control. The lights on the box change as before. Is it most likely that the box is non-functional, the TV is shot, a coax connection or cable is bad, or the amplifier is gone? Can any of these be tested with a simple multi-tester?

If it is the TV or box and I replace the TV will a 32-inch LED LCD HDTV operate directly from the amplified antenna? I prefer not to get an additional satellite control box and system.