Hello Steve thank you for answering me,
I answer with the same sequence of your questions:

the details visible when it stops working are black screen and a continuous whistle and everything is blocked nothing works, to restore the functioning I have to physically remove the power to 13.8 volts .

If I switch to a memory channel programmed in the 6-meter band, it makes the same fault.

It is not a problem related to heat, the defect is manifested both on hot and cold radio.

Yes uhf the problem is the same, same defect.

I do not think it's a problem with the flexible cable, the radio has never been opened, never repaired until now.

I have already tried to reset the cpu as described on page 25 of the user manual, but unfortunately the problem remains.

These are my answers. What do you think if I replace the cpu? I am a process technologist and I work in an electronic board assembly company, I have all the technology available for electronic board interventions also bga step 0.4 mm qfn qfp, all electronic components in general. I also have the possibility of doing x-ray, so it does not scare me to replace the components in my radio. The CPU has the firmware inside? Is it possible to read it before replacing the cpu? Is the firmware protected by reading? Thanks again for your patience, I send you a bottle of Italian wine !!

Ciao, Stefano
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