High Speed jet bumper won't turn off

Shavenyak

Well-known member

Donor 2023
Joined
Apr 16, 2008
Messages
3,352
Reaction score
611
Location
Sarasota, Florida
I'm 95% finished with a playfield swap and as soon as I turn the machine on, the lower left jet bumper activates and stays activated until the fuse blows or I turn the machine off. The switch that activates the solonoid is fine; that is when playing with the switch, it doesn't turn off. I'm not sure where to go from here?
 
The lower left pop bumper is transistor Q69 on the CPU board. Test it with your DMM to see if it is still good. If you're not reading between .4 to .6 with blk on the middle and red on the outer legs then change it out. I think they're TIP102s.
 
This sounds exactly what is happening to my F-14 right now.....
 
Bumping this.
I was diagnosing an in-op center pop bumper on my flash gordon tonight. I 'experimented' on the working pop bumper and caused it to stay on at all times now. Pffffft lol.
I bridged both sides of the small diode on the switch, then the problem surfaced. I tested the diode out if circuit and it passed. Im guessing I fried the transistor after doing some research.
I love a good mystery...ill report back.
 
Back
Top Bottom