My Alien Poker has received a lot of repair attention lately. It even has received a new Rottendog MPU/Driver board combo. Important to note, the drop targets, though previously a bit sticky and inconsistent, generally worked OK when this board was installed around a month ago.
To fix the sticky inconsistency of the drop targets, they have been rebuilt with new springs, horseshoes, individual PCBs, and a few other parts. They now mostly work great. So what’s the problem?
As you (experienced pinball player that you are) know, when you hit the targets from right to left (10, J, Q, K, A), the targets should stay down. They do. Further, when you hit a target out of order (e.g., Q before 10 and J are completed), it’s supposed to pop back up. It does, except…
I can consistently get the targets to screw up by hitting two targets at once. For example, if no targets are down and I hit the Q and K, the Q will go down and pop back up but the K has a really good chance of (incorrectly) staying down. No other condition other than hitting two targets at once seems to cause any problems. But, this 2-target thing is a relatively big and consistent problem.
Because the board is new and definitely allowed the drops to work correctly in the past, I’m ruling it out. The new PCBs (http://www.marcospecialties.com/pinball-parts/1B-2001-124) are certainly suspect here, but I’m at a loss to dig in and fix this problem beyond this general idea.
Any suggestions you provide will be appreciated.