Code 10 Ford radio?

So, my code works, but I am using an AC 220 to DC 12 converter, not car battery....
and due to constant switching power on off, error code 10 appeared on display.

I found that button 6 needs to be pressed while powering the unit....

It doesn't work by me. Code 10 is always on, i cannot turn the unit off,

and holding button 6 gives no result.

Any idea? ( it's a model : 2014)
Please advise, I was repairing the cassette mechanism, now the whole dam.n thing isn't working.