Hi all.

I am having a weird problem on a TMNT. The right flipper works fine in-game but does not register in switch test. I have checked the connectors and header pins on the flipper board and on the MPU and they are good. The MPU is a new Rottendog board. I checked continuity from CN1 on the flipper board to CN8 and CN10 on the MPU and everything is good.

According to the schematics, the flipper switches should have 0.1ufd capacitors on them. However, the flipper switches in this game are micro switches rather than leaf switches, so it doesn’t make sense to have capacitors. So I assume the schematics are wrong. Can anyone confirm?

In switch test, right flipper button hits will sometimes trigger the trough switches (weird), but never the right flipper switch. I can manually short the right flipper switch column and return between CN8 and CN10 and this will trigger the switch closure as expected in switch test. I just can't get it to work using the cabinet button.

I'm at a total loss here; appreciate any help!

I'm convinced this must be a component issue on the flipper board. Which components in the switch circuit are most prone to failure?

I retested all of the components on the flipper board and Q5 gave suspect results. Q5 controls the switch drive and switch return A. I replaced it with a PN100 and the flipper started registering properly. So, fixed at last.

IMG_5541 (resized).JPG