Pin 12 is high in attract mode. Pin 11 no reading in attract mode or with game start. Pin 13 low in attract mode
and low with game start.

Display fuse on power supply blown which probably explains the display. Replaced fuse and it blew again. Ordered a rebuild kit from Action Pinball.

Traveling for work so will pick it back up next weekend. Damn work!

Amen to that. Back from work travel and back at working on the board. I am first tackling the power supply repair. I replaced C1 and C3, and a bad diode on the power supply. I am now getting 100 volts from the power supply to the display and the corresponding 2 amp fuse is no longer blowing. However, the display is still not working.

I have not tackled the jumper to address the bad trace. Would like to get the display working first so I can at least have diagnostics.

Thanks

Blanking LED on MPU is lit, and there is 5 volts from the power supply to display.

Okay trying to diagnose the blanking signal. U51 pin 4 is pulsing in attract mode. U43 pin 3 is low.

Still need help.

Okay trying to diagnose the blanking signal.

Attract mode

Pin 4 U51 is pulsing
Pin 13 at U36 is pulsing
Pin 12 U36 is pulsing
Pin 6 u43 is NOT pulsing

Pin 6 u43 showing a constant 1.39 volts

Both sides of c57 are pulsing.

I also checked 1J3 pin 12 and it is testing high. The leg of R137 prior to the blanking led is also showing high. It does start low and then switch to high. u43 pin 3 also shows high. What the heck is going on with this board?

U55 pin 1 is high. Pin 2 at 1J22 is low - the pin that sends the blanking signal to the displays. So is something else going on and it is not the blanking signal? I still don't understand why I am getting no pulse at pin 6 of U43, and yet the blanking circuit appears to be working correctly.

Pins 1-8 on U44 have no signal, but shouldn't that be the signal to the first score display?

So u44 pins 1-8 defintely not working. Pins 9-16 are sending a signal but displays 2 and 4 are not working.

Yes, the blanking signal is getting to the display. The Xpin has exposed pin connections and checking pin 2 on the display with the ribbon cable attached shows a low signal.

Completely stumped with this board.

Displays are now working!

An odd thing now with the sound. It works during the diagnostic sound test. The music, however, does not play for each player. For example, music and sound for player 1. No music but target sounds for player 2. Music for player 3, ....

Grumpy,

First, THANK YOU! You have been terrific helping me work on this. I have learned a lot. Now if I can get the sound issue fixed. I am going to start a new post and mark this one as resolved

I finally decided it was well beyond my capabilities so I sent it to Ed Cheung. Here is what he said. The last quote makes no sense to me but maybe you understand it.

"Several problems with the solenoid circuit that I repaired and your displays had a really odd problem. A few of the outputs were shorted together, so toggling them all (my standard test) showed no problems, but attempting individual output did not work."

"On System 11, the CPU controls each of the segments of the display, but in a bus/multiplexed fashion. The segments on the top row have their own control lines, and the ones on the bottom are separate. Then, each of the columns in the display have their own ‘strobe’ lines. There are 16 strobes corresponding to the 16 digits across. It is really kind of complicated to explain words."