problem solved, I made very stupid mistake in the upgrade procedure.
btw, the reason for the firmware upgrade was a selftest error in step 3.
This is fixed by re-calibrating the TinySA-ultra.
met vriendelijke groeten, Gerrit
(btw2: TinySA is a fantastic tool, must have for all hammers
and compliments for the designer Erik and lots of compliments for his after sales support)
