Lorenzo,
? I'm just guessing the cause of the problem because I can't do it to see and measure it.
Please remove the pcb from the housing (so that the housing is not damaged during soldering).
There are two ferrite rings near the antenna connector and a diode (D27, D28) nearby.
You should measure these diodes at direct current. You can easily unsolder it and put it back in the same way.
They provide the control signal for the output signal measurement.
These are 1N63 or 1N60 type Ge diodes. If these are damaged, there is no output signal status display.
If you manage to get it, it is worth selecting ones with almost the same conductivity and incorporating them.
Don't ask how I know.
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Gyula HA3HZ
HA3HZ