Quoted from Mathazar:Does the chart with the expected vs. actual firing order offer any clues?
Yes, the chart very much points to the problem.
As dothedoo mentioned, there are 4 signals from the MPU board to the SDB that select specific momentary solenoids to activate.
These signals are marked PB3, PB2, PB1 and PB0 on the schematic from the MPU board at connector J4 pins 1, 2, 3, and 4 respectively. They go to the SDB on J4 pins 3, 4, 5 and 6 respectively.
Below is the binary logic state of these signals (derived from the SDB schematic) showing what solenoids their combination activates.
Mapping out which solenoids are firing in the wrong order from your table, your problem specifically indicates that signal PB3 is stuck on a logic high "1" state at the SDB meaning there is an open circuit on this wire signal.
It's a red-white wire and it comes from MPU board connector J4 pin 1 and the destination is the SDB connector J4 pin 3. Check/reterminate the terminals on both ends - also check the soldering on the J4 pin header on the back of the solenoid driver board.
PPPP
BBBB
3210
==========================
0000 Saucer
0001 Chime 10
0010 Chime 100
0011 Chime 1000
0100 Chime 10000
0101 Knocker
0110 Outhole
0111 Pop Bumper Bottom Left
1000 Pop Bumper Top Left
1001 Pop Bumper Top Right
1010 Pop Bumper Bottom Right
1011 Slingshot Left
1100 Drop Target Reset Left
1101 Slingshot Right
1110 Drop Target Reset Right
1111 --
Fredericksburg, VA
