Saturday May 18, 2024

Jungle Lord Update #6
  Posted by: AceBHound on Nov 28th, 2010 9:47 PM
I finally got the missing 100s digit on the 1st and 3rd player displays working on the Jungle Lord pinball! After replacing the 74154N on the MPU board the 100s digit was still missing from both displays. Used my logic probe to poke around on the master display board while the machine was on -- and was lucky not to hit anything high voltage (next time maybe I'll put the machine into display test mode and then remove the high voltage from the machine). The logic probe told me that the 74154N was pulsing properly, also the input pin on the 4069 hex inverter IC10 was getting the pulse from the 74154N, however the output pin on IC10 was locked low, while all the rest of the output pins on the 4069 ics were pulsing. So I was pretty sure the IC10 4069 chip was bad. Replaced IC10 with a new 4069 hex inverter over the weekend and that fixed the problem. The only other thing I noticed was when in the display test mode as it cycles 1111111, 2222222, etc the commas light up for the even digits but not the odd digits. I'm not sure if that's how it should be or not, but didn't have time to play around with it enough to see how the commas work during a game.

Next I'll have to remove the MPU board again and clean up the minimal battery corrosion damage around the solder pads where I cut off the battery holder. Then add a remote mounted battery pack onto the board so it stops booting into audit mode and keeps the high scores when the pinball is off. Then some more testing to figure out if there's anything else not working 100%. I also think a few switches around the ball trough might need further adjustment since sometimes it doesn't detect when a ball is lost between the flippers. This Jungle Lord has given me one heck of a fight, but almost there!

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