I picked up the Lost World I have listed for sale as a partial project.
I got it playing with some cleaning, socketed one 40pinner on MPU and some new fuses.
I got the game to play, until I hit left saucer. That blew PF fuse. I tracked it back to Q8, blown. (Q8 was already blown, I got game to play originally with no solenoids, which I tracked back to missing 1A PF fuse, once installed fuse, game played until I hit left saucer, blew fuse, then tracked back to Q8 being grounded)
Replaced PF fuse, unhooked double wire to Left Saucer coil.
Game plays fine now, if i hit the Left Saucer, I have to pop it out with my finger.
I replaced Q8 with TIP120
Reinstalled Solenoid Driver Board.
Tested game, plays the same (obviously), power on did not fry the new Q8 to ground.
BUT, when I go into test mode for solenoids, it blows the PF fuse, I am 4 fuses into the repair and don't want to blow another one, but I cant say for sure which solenoid it got to before it blew the fuse, but think it was 06?
I checked the Coil on Left Saucer, got 0ohms resistance with leads both ways.
I snipped a leg off diode, test diode it tested open.
Coil has not visible signs of being burned out, label is still attached, nothing crispy, moves freely.
With Diode removed, coil tess 10.xx ohms just like the right saucer so I think the Q8 transistor and diode paid the price but the coil may be intact.
New Diodes in transit.
I am pretty new to pin repair, am very comfortable with video game repair and have a decent bench.
Wondering what else I may need to check or want to check on this thing before it eats another 10 fuses.
I am also looking at getting the breakers for diagnosis so i can stop blowing out fuses left and right.
Any help is appreciated.