Nice cabinet. Did you set the Altek board to free play? How does J4 plug look at the Altek board? If the original had battery damage, I’ve seen it crawl into the pins on the J4 connector, so it’s worth looking to see if any of those pins are green.

I’m not sure where to go from here. Have you tried a reset on the Altek board?

You might try resetting all the switches in case one isn’t quite making.

Do you have another machine to try the Altek board in to see if the issue is with the board?

MRM - I don’t know how you saw that. On my phone, I don’t even see any of that. Good catch. Makes me think there may be other connector issues.

If I’m reading the manual correctly, the zero in switch test indicates there are no stock switches. If the ball is not installed, then this is good.

I think your displays are operating properly. The Altek has decided to register 30 credits. If you want to reduce that, two options: A:switch Altek from free play, then start four player games, then switch off, repeat. Once it gets to a number you’re comfortable with, switch back to free play. B: Turn off the credit display option.

Always power down before changing any switches, and yes, the Altek board needs that ground screw.

Concerning using two 10 pin connectors - not a good idea. I am not sure how you could idiot proof it to keep both of them from being plugged in wrong. I would clean the existing twenty pin connector, and if it looks good, use it with new pins.

If you don’t have the manual, go to IPDB and download the manual. Look closely at the connectors in line with the knocker, and remove and look at the pins in the connector. Let us know.

Is the right flipper stuck in the up position when power is off? If so, you have a mechanical issue, otherwise it’s electrical.

I still keep coming back to connector issues is a big part of all these problems. I think MRM would like to see pics of all the boards, especially the SDB, rectifier board, And the connectors on the Altek board, especially J4.