Thank you Joachim for the complete and patient answer! You´re always there for us.
I am aware of all the steps but I never did the 7 (transposition gate zeroing). It seems that all my M boards are off (none of them are close to zero).
My PSU is calibrated and solid, but I have problems getting accurate voltages on the KAS board (page 3)..
step 1 -ok 4,00V
step 2 - 125,7mV instead 125,0mV potentiometer to the max
step 3 - 125,1mV instead 125,1mV
step 4 - 131,4mV instead 132,4mV potentiometer to the max
Increasing the voltage on TU to around 4,04V helps for step 4 but the others go south.
step 5 and 6 ok.