Williams Black Knight (Williams, 1980) issues

[ArtGuyDeluxe]

I recently acquired a Black Knight machine. It starts up fine but when I initiate a game the ball will not launch, and the drop targets will not reset. The flippers, lights and sounds all work just fine, but the manga-save will not release the balls when I press the release buttons. Is this a fuse issue? If so, which one?
Thanks!

 

[pinballdaveh]

if the magna save is somewhat working the solenoid fuse is prob ok. i would check or change the 40 pin interconnector that connects the cpu to the driver board. this connector is mostly data lines , when it goes bad all kinds of weird problems can happen.

 

[ArtGuyDeluxe]

The magna-ve doesn't work at all, other than the magnets holding the ball, which they would do with or without power. Thanks!

 

[Coil_Smoke]

I don't think there are any permanent magnets in those magna-save devices. They are just electromagnets. They should not hold a ball when de-energized. Maybe the pole piece/core has become magnetized? Do they still hold a ball when the game is off?

The outhole kicker,left drop target share some same connectors and column in the matrix . Like 2P11&8P3 . Give them a good wiggle and re-seating.The IPDB has lamp and solenoid matrix but no complete manual. That chart alone could be a lot of help tracking this down. It does mention relays that control those Magna-save coils. Look for a broken wire or bad solder joint in drop target reset, ball trough solenoids circuits under playfield. Gray with Brown,red,orange trace wires. going to, from and between the playfield features not working.http://ipdb.org/search.pl?any=Black+knight+1980&search=Search+Database&searchtype=quick

 

[ArtGuyDeluxe]

It seems to be a loose wire somewhere. I was wiggling wires near the rectifier and the whole thing suddenly fired up and seemed to work fine. After a few more wiggles, I managed to zero it down to connected wires to the lower left of the rectifier. After a couple of days of clean operation, it mysteriously stopped, and no amount of re-wiggling seemed to want to bring it back to life. Arg! I was so close!

 

[pinballdaveh]

the bridge rectifier female connectors can be tightened by gently squeezing them with a needlenose pliers. i have also seen them soldered right to the rectifier lugs.