So this thing may become more in deep than I expected.

Problem:
When power it on always kicks two times,sometimes one time but very rare.

Only happen when I power on the machine.If I go in test menu and exit don't do it.

What I did until now:
1.Replace the switch on auto launch assy whit new.Testi it and it's fine.
2.Checked all optos and especially these on trough assy.Everything is fine

One thing happen today when I begin to trace Green/Brown wire and little shake the wires-thw kicker activated rappidly like never before.After that it worked like the present problem.

The game plays fine but this thing is not right for me.

Changed 16-opto board no difference-same problem
Tested with working opto boards on trough mechanism-same problem

But how is normally to operate the machine?
It want 4 balls.
Is there need to have a ball in the left lock mechanism under the small ramp?
Because when I put 4 balls in the trough mechanism sometimes when I begin to play(push start button) it load it automatically there and in theory I begin to play with 3 balls in trough mechanism.
But sometimes when I begin to play don't load it and play with 4 balls in trough mechanism.
At both situation the game plays fine.

If there need to have ball in lock mechanism under the small ramp and I have 4 balls in trough mechanism,isn't it normally when I power on the machine to load it by itself automatically,not when I push start button?