After a ton of time working on this machine, I am at a frustrated level...my mind is blown!! LOL. I am hoping some pinsiders with more ideas that I have run out of, can point me in the right direction. Here is my issues..

1) Basically, doing a switch test, when the ball in the trough 3, along with holding the right flipper button and the other ball in play - hitting the right pop bumper, causes a VUK switch reading. This causes the ball in trough 3 to then eject onto the shooting lane, ready for play while the other ball is busy still in play.
The same situation arises with similar combination - ball in trough 3, holding down left flipper button and center pop bumper - VUK reading and ball comes out onto shooting lane to play....at this point I am thinking it is something with the Rottendog MPU, as I have changed all of the diodes on these areas, based on the switch matrix video by TerryB. I am not sure where to go next other than trouble shoot that board..........ideas???

2) My right slingshot doesn't read in the switch test, either, but it works fine......curious how that can be...

3) Sound woes continue......

Loud buzz, gets louder as I turn up the volume knob - the sounds are all clear and loud, but the music is so faint in the background it needs to be turned all the way up to even know it's there at all....

I do the SINE test and the signals are there but no louder than the music - has to be turned up all the way to hear those, as well. Both ROM's sounds are clear as can be.

4) When Lazer kick is activated, the saying "get off the grass!!" no longer plays, but it used to.

So that's it. If anyone can help me with these issues that would be great......thank you and Happy New Years!! I have attached pics of the switch matrix, my notes, and my back box so you can see what boards I am using. Outside of the sound board, every other board is aftermarket.

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Thank you for the input.....i have checked all the diodes on 2 and 6 before I made this thread (my bad for not mentioning it), removed and tested with multimeter...all read good. I couldn't find one bad diode.

MC3403C is the chip, are other MC3403 versions comparable as I cannot find the "C" version for sale anywhere...

I will tinker with the slingshot switch today to see if I can get it to show up on switch test.

Thank you again.

Sound issue SOLVED.....

I purchased another board as a gamble, as it was listed as not known working, to see if it might solve the problem.... the board works great! Aftermarket speakers rock!!

My original board has issues.... guess I'll shelve it for now and tinker with it another time.

Now, back to that switch matrix issue....