Hi,
I've got my 1984 Williams Laser Cue back after storage for 7 years, but the solenoid fuse blows after a few minutes of play.
Playing with Fluke connected to solenoid fuse to measure current, what usually happens:
- The game starts up normally, game starts. Fluke measures 0A
- All solenoids work as expected: drop targets are restored to up state and game starts. Fluke measures 0.160A in rest, with few Amp spikes when solenoids are active.
- After playing a few rounds fluke shows continuous current of 4.5 amp and fuse blows shortly after.
In this state, drop target 1 is up, the 2 to 5 are down, and the solenoid for target 1 is powered all the time. Disconnecting 2J11 removes the load, so the problem is somewhere on the bottom board.
Powering off / on does not fix. First drop target is restored but the solenoid keeps active, causing the high current.
Entering solenoid test shows normal results: all solenoids are activated for a short period.
Not sure where to look - the problem does not seem to be electrical or mechanical since the normal solenoid test runs as expected. The problem is that the software keeps the solenoid active for too long for some reason. The switch on the backdrop seems to work OK measured DC, still need to connect a scope to see if it works normally in the scan matrix.
How does the software decide how long to activate a solenoid; does it expect feedback from the switch to see if the backdrop is acually going up, and does it keep current flowing as long as it is down?
Any help very much appreciated.
Thanks,
Zevv