Montreal, QC
Ok, The right slingshot on my Data East Tommy is locking on.
- When I first got it ... the coil was not working at all. I found a lack of continuity on the Blue/Green wire going from the coil to CN19. Replaced that wire ... and the coil worked (but locked on).
- Replaced the TIP122 with a TIP 102 ... and the coil worked a couple of times then locked on again. The old TIP122 was bad.
- Next ... Suspecting the coil Diode ... I actually swapped in another (working) coil with fresh diode. When I clipped and tested the old coil diode ... it seemed fine though. I then proceeded to replace the TIP 102, the pre-drive transistor, and the 7402 chip (adjacent CN19).
- The coil worked fine for 5 games. Shut it off. Came back the next day. First game noticed that the coil was locked on again.
- I haven't yet tried changing the diode and small capacitor that run in parallel on the unused reflexive circuit (next to CN18). Gonna get those parts today.
*** While I am out picking up components ... I just thought I would ask if I am missing something. Anything else in the circuit I should be testing? I had it working for half a dozen games after I replaced the coil diode. So I don't think I am blowing transistors because of a bad coil diode. Can anything else cause the TIP102 to die???
*** One other small note: When I replaced the 7402 chip. After sucking up all extra solder and prepping to mount the new chip, I noticed that two of the holes in the board were pretty much adjoined. What I mean is that there was no green board separating the metal contacts of each hole. I looked at the 7402 just above it ... and that one had all pin holes separated from each other. Anyone know if the board is meant to be that way under the lower 7402 chip next to CN18?
Thanks
Falls Church, VA
