Hey all! Just got JD all put back together and everything was working great except the center scoop wasn't registering. I turned the game off, raised the playfield and realized I left the connector to the switches disconnected. I re-connected the connectors, lowered the playfield, powered the game on and went into coil test to eject a ball to manually test the scoop. As soon as I closed the coin door, the machine shut off like it was going to reset but no lights came on and the launch coil locked on and the planet and crane arm continued to run. I powered the game off immediately and checked over things. I smelled a faint burning smell but couldn't track it down. I checked over things below the playfield and in the backbox. All looked good so I turned the game back on. Nothing appeared to lock on but now the planet and the crane continuously run but no lights come on, DMD is off and the game never starts.

I'm not sure where to go from here to start troubleshooting and I certainly don't want to do any damage. Anyone kind souls care to guide me in the right direction?

LTG ForceFlow PinballManiac40 Thank you all so much for the help! I tested all fuses on the driver board and none of them were bad. (I did pull each one prior to testing).

I also left the recently connected connector disconnected but I am sure it is correct by my pre-teardown photos and I labeled each side of the connector.

Ribbon cables were seated properly and game worked fine for about a week prior to this occurrence. I played the game for a while before realizing the scoop/jackpot shot was not registering. To rule them out, I went ahead and re-seated all ribbon cables.

I tried firing up the game and nothing happens now. No lights, no bong from the sound board, no spinning deadworld or moving crane arm. All the LED lights on the driver board light up except LED 3 which is normal and LED 5 which is not normal.

On the CPU board, D19 and D21 are lit solid and D20 appears to repeatedly flash one time. According to the manual, it says U6 is bad. I did remove and re-seat U6 but it did not help. I do have another U6 chip running later software but I didn't change it out because I don't want to risk damage to a second ROM.

Should I go ahead and replace U6 or are there some other troubleshooting steps I should take first? Thanks!