Some work on the MGOW this week:
I put in a Swemmer MPU & backbox A11 chase light PCB (fixed my chase lights problem!), & also a Rottendog power supply board.
This makes my MGOW is now much better, but it's not quite all there yet.
In short, the game plays OK, but none of the 4 pop bumpers reacts when balls hit them, the bottom left pop bumper ring switch doesn't score points or make sounds when manually moved, & the ramp tube chase lights don't illuminate.
So, my 2 main questions are:
a) Where do the wires for switch 43 (bottom left pop) go? I'm guessing it must be a bad diode, since I put in a new MPU? Hootowls, I know you pointed one out in a previous post, but that doesn't seem to be correct. See below.
b) I seem to have no 5VDC for the 4 pop PCBs & the ramp tube chase light PCB next to them. Where does the 5V come from? The Rottendog power PCB puts out a nice 5V on all 3 of its connectors. Grounds for these 5 little PCBs all check out OK.
Details of what I've done & checked:
1 - On power-up, the LEDs on the 4 pop bumper PCBs don't light. Is this correct behavior? I'm guessing not, since I don't read +5VDC on 5 of each pop PCB's connector.
2 - During gameplay, when I manually pull down each pop bumper flange ring (which the solenoid is supposed to actuate), the game does react properly for 3 pops (sound effect & points added to score). The game does not register when the bottom left pop flange ring is moved down.
3 - In self-test 18, all switches seem to register OK except for 43, left bottom pop bumper.
4 - In self-tests 16 & 17, all other solenoids fire OK. There doesn't seem to be a self-test that triggers the 4 pop bumper solenoids.
5 - I checked continuity between all 4 pop bumper's "upper" leaf spring (the one that the skirt closes, not the one that the flange ring closes) & pin 4 of the A8J1 connector on each pop bumper A8 PCB. Good for all 4. So, all 4 pop skirt switches are still connected to the 4 pop bumper PCBs (so I don't think the 43 switch diode is bad).
6 - I also confirmed continuity between each A8 pop bumper pin 1 on A8J1 & each pop's coil. All good.
7 - Grounds all check out for the 4 pop PCBs, ramp tube chase light PCB, & the ground strap under the PF.
8 - I studied the bank of 5 diodes at bottom right of the PF (when open & propped up), next to the tube chase light A12 PCB. Using my multimeter in continuity mode, the left one seems to be open whether I put my COM probe on top & + probe on bottom, or vice versa. The 4 diodes at right show continuity when I put my COM probe on top & the + probe on bottom & show open when I reverse the probes, so it seems as if these 4 diodes are good. But I can't find continuity from these diodes' legs to anything pop-related on the PF or PCBs...