SONY STR-DE545 Stereo Amplifier/Tuner no radio

[TEX]

I an integrated 5.1 tuner/amp.

Will not output anything from the tuner. Has a slight hum but nothing
else. Doesn't seem to pickup any stations either. All the other inputs
work fine.

If i unplug the tuner module off the board the humm goes away. How can I
confirm it is the tuner module before I order a new one.

I found some schematics that lables the pins of the 15 pin tuner:

Stereo
Tuned
T.Mute
S.Data
S.Clk
DO
S.Lat
L CH

but i have no idea what sort of signals I am suppose to expect from
these. Any help appreciated.

Thanks

TEX