Worked on a Bally " Dolly Parton " on sat . No pics unfor
Another service and fix , No Controlled lights and 2 coils not working.
. The coils problem ended up being a bad 6820 PIA chip on the MPU. After much searching! ( altek replacement already installed in the game ) This chip handles the momentary solenoid data . Coils fixed!
Now the Controlled lamps? No power at test point? What to do , All bridges tested good, i like to test them all anyway , but this problem was with the Diodes .
New Diodes had been soldered on to old legs!! , De-soldered these properly and replaced the Power Supply's 4 x 4007 diodes that the Controlled lamps power goes through . Had had some work previous ( Shoddy See above ) and re-soldered some connectors etc on the power supply, Also tweaked the fuse clips , they tend to lose the tension. Lamps fixed! .
Fitted new 12v filter cap to SDU , Had the original still , This needs to be done on most of the Bally/Stern games i repair .
Game in great condition ,gave it a good clean , some new rubbers , a new shiny ball! Tightened up a loose flipper shaft. Got all the lamps going again GI's and all the controlled lamps . Game is being used the next Saturday night for a 18th , So will check up and see if its all good still during the week ...
