Citroen c5 radio problem

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I have problem with 2005 citroen c5 radio. Guy replaced battery and after that radio wont turn on. Nothing works on radio panel , not even AC button.
I did not have lexia at the time since i borrowed it to friend but i will have it in next few days, so i entered diagnostics with FVDI but could not do much only when i entered RADIO diganostics it turned on and worked without problems - all buttons worked but moment i exit radio diag it shuts down. Error that fvdi showed is F905 i cleared it but it just showed up again and i could not do much with fvdi.

I think radio is VIN coded with BSI and it does not have any radio code to input? Could it be BSI or radio problem and can i do anything more with lexia?

I know that F905 is Fault on the audio inputs of auxiliary No 1 but i am thinking that there is no any physcial problem like short circuit since when i enter diagnosis radio wakes up and works , all speakers, all buttons - volume, stations etc....

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no ideas here?