I have an odd one. I recently was working on my Jungle Lord. It had a few small issues. Most of the issues (after searching around here) showed they were all related to the header connector between the CPU and relay board. So I took all the boards out of the game. Did all new caps on power, sound, and CPU boards. Did all new pins and sockets on the header connect the CPU and Relay boards. Flowed solder on all connectors on all boards. Went over all boards and checked, re-flowed solder on anything and everything with a fine tooth comb.

So now the game powers up just fine, all the lights are working it's doing attract mode just fine the speech is talking in attract mode just fine from time to time but it won't coin up or start! I figured let me put the game in free play and see what happens. I go to number 18 in the menu to set it to 00. So into test mode I go hitting advance with the door open, and when I get to any setting the numbers just take off on the display like I'm holding down the start button to adjust them. Checked all the switches nothing seems hung up or touching. Strange part is it never had this issue before. I also installed NVram and took off the battery holder and the NVram is working as it should.

Looking for some trouble shooting start points. Quick search didn't show much on this. Thanks!