Gottlieb Black Hole (Gottlieb, 1981) captured ball problem

[PinballDude369]

Hello,

My Gottlieb Black Hole pinball has a problem: when
you lock a ball into the lower playfield capture hole and then end up
finishing the game with that ball still down there the game doesn't
eject the ball first, wait until it comes back to the main playfield
to drain and then end the game completely. Instead, the game ends
while leaving that ball down there. When you start the next game it
then ejects that ball, the ball comes back to the main playfield and
drains. However, when you do start that next game a ball is released
like usual into play and once the lower playfield captured ball
finally gets back up to the main playfield and drains the machine then
releases that ball into play as well. You end up starting off a new
game with two balls instead of one. Can anyone tell me what's going
on with this? I'd appreciate it. I've posted this question before but it's still not answered.

Thanks,

Rob

 

[pinballdaveh]

using self test button advance to step 18 switch test. its looking for closed switches. if none are found 99 will be displayed. while in step 18 manually close the lower playfield captive hole switch and see if the machine reconizes it with a number. that switch munber can be found in your manual if you have one. if it does go to step 20 memory test , if all memory is fine number 99 will be displayed. if all that is fine j5 and j6 lower left and lower middle connectors on the cpu control board need to be checked for loose wires and corroded connections. circuit board edge connectors can usually be cleaned with a pencil eraser. if all that gets done with still having problem prob. a gate chip or inverter chip might be at fault. i dont have the board schematic or wiring diagram to tell which one. or it could be poss. a bad prom or prom socket.

 

[PinballDude369]

Found a problem, now just need to know where to go

using self test button advance to step 18 switch test. its looking for closed switches. if none are found 99 will be displayed. while in step 18 manually close the lower playfield captive hole switch and see if the machine reconizes it with a number. that switch munber can be found in your manual if you have one. if it does go to step 20 memory test , if all memory is fine number 99 will be displayed. if all that is fine j5 and j6 lower left and lower middle connectors on the cpu control board need to be checked for loose wires and corroded connections. circuit board edge connectors can usually be cleaned with a pencil eraser. if all that gets done with still having problem prob. a gate chip or inverter chip might be at fault. i dont have the board schematic or wiring diagram to tell which one. or it could be poss. a bad prom or prom socket.

I did the step 18 check and on the display it flashed: "15" and then followed with "25." I checked my manual for those two switches and they are the two which are located in the main floor ball drain area which load the balls and give you a new ball for each round of play. I didn't know what I should do from here. I cleaned the connector on the control board and checked for loose wires and corrosion, but all looks fine (at least to me). What should I do now?

Thanks so much!

 

[pinballdaveh]

remove all 3 balls from playfield and do self test 18 and 20 again.

 

[Itchigo]

Push all the chips in on all boards with your thumb- gently. You will hear a crackling when pushing them in. Many times it's just a poor connection at a point on the chip.