Hi,

When the Mini playfield is down (level 1), when the ball hits the central target and activates the 2 locks, then the switches 71 and 75 (normally used for levels 2 and switched on each time the left and right grey button are hit) are triggered 3 times each without action.
The 2 corresponding columns of red lamps at the left and at the right of the matrix are lit - see attachment -.
The counter of hits which is initially 15 for the level 2 is decreased by 6.
Also when the ball hits metallic parts of the MPF - level 1, the same happens for one contact at a time. It can then happen that level 2 is reached with a counter at 0 and the MPF goes immediately to level 3.

I think of bad contacts with the level 2 optos, but I do not know what to look at. The voltage is good at the 5 receiving optos and varies as expected when the grey button is pushed.

If someone has an idea about the problem, you are welcome to share it

Thanks

DSC_0153-921.JPG

Ok sorry for the confusion, I think what I explain is clear and it is not:

- Start
MPF on level 1 (level 2 not accessible)
MPF level 1 Locks inactive
counter level 2 =15
matrix lamps are off

- Ball hits the central target
MPF level 1 locks activated
Red lamps 1,2,3 of left row are lit (with the sound made when a mushroom button is pushed)
Red lamps 1,2,3 of right row are lit (idem)
Counter level 2 is now 9

- Ball hits once a metal parts of the MPF (surrounding the lock holes)
Red lamp 1 of second row is lit
Counter level 2 is 8

(- If the Ball hits 8 more times a metal part, all lamps are lit and counter level 2 goes down to 0)

- Ball 1 locked - Ball 2 locked
MPF goes to level 2
counter is 8, so only 8 hits on mushrooms (and not on the left/right mushrooms) are needed to go to level 3

=>>> problem should be 15 when entering level 2

Is it more clear ?

Thanks

Thanks wellarmed,

I even have the leds so I can replace and resolder.

Only one question: I measure good voltage on the 2 soldered pins of each receiver. Do you confirm that I have to re-solder ? tks

Thanks all for the good advices. Last time I pulled the mpf and checked the opto bank, the 5 diods were lit when looking with a numeric camera. but if I understand the detailed explanation, if the IR is not soldered properly, it can happen.

I will re -solder and keep you posted. many thanks

No, I wrote a new message asking if I had done something wrong when soldering new leds, because it did not work.
But the led reseller had swapped the "Transmitter" and "Receiver" leds, so I had worked with the wrong type. Just in case, I tried the other type and it worked.
I have to stop today. I keep you updated when done

I changed the leds of the optos in error and, miracle ! it works, no more side effect when hitting the MPF with the ball.

Hope it will last for a little while

Thank you all for the help