working on a Laser Ball. Came to me with lots blown fuses. I found the reason why. The 5V power connector to the driver board was plugged into the ground connector location on the driver board. Now the real problem. The 18V fuses were also blown --- The controlled lamp power to the driver board was plugged wrongly, but I don't recall which place. None of the connector keys are in the connectors. With all connectors correctly positioned the game works now, BUT no controlled lamps.
The displays are not working correctly and likely is a master display board problem that I am putting off until I can get the controlled lamps working.
So on the bench with a logic probe I find that the lamp driver section inverter chips 7406 are not working. I replace both 7406 chips and go ahead and replace the 7408s with 74F08s while the soldering iron is hot. Does not help and I am sad that I may be faced with lots of transistor replacements. Also I was hoping the controlled lamps on the playfield were burned out, but that is not the case.
The sound board escaped damage as it was mounted upside down and mis-cabled as well, but only the speaker and volume controls mis-cabled. I sold off all of my old spare boards so I have not alternative but to fix this driver board. I don't remember the correct voltage measures for the transitors when the meter is set to diode test. So I am going to have to research this out.
Who removed the connector keys?????? Vent over....
