HP 41C Video interface test. Howto?

[tribidouille]

I went back to the documentation.
For the recall and for other users: the frequency to set the TV to is 61.25Mhz for the 82163A (usa) and 62.25Mhz for the 82163B (eu)
The adapter referred in the manual is to be allow to switch between the antenna and the cable input if I understand correctly.

But anyway... I print nothing else than these triangles and the 41C's flag 55 says "no printer"...