Dears,
I would like to send big "thank You" to all replies off-list.
It is really appreciate help for us in order to make repairing of this K1 step by step.
According to your hints we made an inventory of his K1 and there is RF board Rev D 2000,
FP board Rev D with Firmware 109E and 2-bands filter board Rev D with Firmware 100...
We will report over there (if it is not too bothering) about our debugging progress.
My 14yrs old son Jakub is really amazed with his K1 even although it is not repaired yet, hi
and I aprreciate it too as he is not focusing on his PC games only...:)
Many thanks for an excellent help and camaraderie to all.
73 - Petr, OK1RP