Here is a Hijack trick for both of you to try with your malfunctioning tuners:

In the player's config.ini file, add the following:

[hijack]
fake_tuner=1

This causes Hijack to force the player to "see" a tuner module, even when one is not (apparently) present. If for any reason a real tuner responds, Hijack then quietly bows out of the handshake, leaving everything functional.

It might provide enough of a timing bend to cause things to work, or it might at least provide some more info. There is also a trace_tuner=1 flag to dump out all of the packets sent/received onto the console serial port.

Cheers