'90 factory radio

[b79holmes]

I recently acquired 1990 Suburban with the original AM/FM radio. I turn it on and it behaves normally, all the volume adjustments and balances seem to work, but the radio won't receive any signal. It seems like the antenna isn't connected, or something.

I plan on taking it out of the dash next weekend to try and figure out what's wrong. Any tips or suggestions about removing it and diagnosing the problem? Could the radio itself be broken internally?

The truck has 260,000 miles and is almost totally stock, so I guess anythings possible.

Thanks,