Working on an 8BD with a few problems. Game would boot intermittently. Went through Clay's guide and upgraded the Solenoid board and replaced some headers and connectors. Game now boots but the the top left flipper is locking on immediately. What should I check for this?

The other problem is no sound. I don't want to leave the game on with the flipper engaged, so haven't dug too deep into the sound issue, but curious to hear what's the best way to troubleshoot this. Connectors or caps a bigger culprit or neither?

I appreciate any help and thanks!

I cut both diodes and both tested good. Measured ohms on the coil and got 0.4 from the left lug (3 wires) to the middle and 3.6 from the middle to the right lug (one wire). Does this indicate the coil is bad? I had an extra solenoid boad, and switched that in and had same problem (flipper immediately sticks up).

Any other things to check for the flipper?

Flipper locks on during power up. Looked at both switches on the lower flipper, and both look good.

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I did not see any short and the wiring looks correct. Focusing on A3J1-8&9, A3J2-1&2, and the flipper enable on A3J3-5. Am I missing any other wires?

I unplugged all the connectors from the solenoid board, and the flipper still locks on. Does this narrow my search at all?

Appreciate all the help so far!

Flippers engages while playfield is up or down. I am getting 8.4 ohms from the black/white wire to the ground braid. Here is some photos of the upper flipper.

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On a side note, I am replacing the 2x, 3x, 4x, 5x drop targets, and the drop target assembly is taken apart. Could this affect the flipper?

dothedoo--you were exactly right! The black/white wire (and another wire) was underneath a screw and was shorted. The flipper is now working and moving to the no sound issue.

I recapped the S&T board and resoldered the header pins, and still no sound. Adjusting the pots all the way does occasionally make a humming noise, but can't get any sounds or speech. Calling it a night, but wondering what the next step is.

Thanks for all the help.

Here's the video of the flashes. I checked the +5, -5, and +12. All were good and the + 12 was about 14. It looks like I am getting 3 flashes? Is this correct? If so, I replaced u11 socket and tried a different 6821 and still getting no sound.

I was messing with the connector and got the sound to boot. Figured the connector was bad and replaced the header and connector, and still getting the no sound. Currently replacing sockets and cleaning chips and waiting for 2 pots to come in the mail.

Any advice one what the next step should be?

Still getting three flashes. It booted once, but haven't been able to boot since. Speaker is good. That was one of the first things I checked. Anything other suggestions?

Still trying to figure this board out. I have replaced all the sockets, caps, headers and connectors, and the 2 pots. Tested the speaker and it was fine. Still getting 3 flashes. I have switched out the PIA and still getting 3 flashes.

I checked the PIA, CPU, and U12 with a probe and found no floating pins. The buffer tested good, too.

Wondering if I need to order u12 (AY-3-8912). Does this chip need programmed or not?

Any other thoughts?

I switched out the PIA with one from the MPU. I switched in another just for good measure and still didn't work.

Thanks, dothedoo! Hopefully with another boardset, I can switch some parts around, or at least check some of the signals.

Forgot to update this post. Sounds is now working! Thanks to dothedoo for letting me borrow a spare board! I replaced u12 (AY-3-8912) and the sounds came back.