Here we learned to know a new dimension I'd never seen before; if you don't beleave I'll invite you to Dresden!
Immediately after starting selftest display showed for short time "REMOTE CONTROL", got dark again and seemed to restart.
Then different activities ran with short times, display on / off, backlight on / off, valve on/off - desaster pure!

Next step: I replaced pcb by new one - the same effect.
The same pcb that I had prepared the evening before without problems showed the same features!!!
It reminded me to first samples of pcb where we also had problems with restarting in power-on-phase.
There we added a second 4700µF capacitor to solve problem.
Next step: I replaced power supply - no effect.
Next: Another power supply, directly connected to pcb - no help.
I checked mains voltage as well as DC voltage - both ok!

Since I couldn't believe that new pcb showed same error by accident I disassembled pcb and went out of the room to the corridor.
I connected it with same power supply to power outlet - and you won't guess: it worked normal! I could touch pcb; no reaction- everything normal.
Then I went with pcb and power supply to room with type F unit, connected it to another power outlet - the same desaster like before.

Do you have an idea what effect we have?