New (to me) game. Data East Jurassic Park.

Row 2 lights are out (Q73). This was clearly replaced and the work was a little messy so I was hopeful cleaning it up would fix the issue. In circuit it tested slightly out of spec to the rest of them. I removed it, cleaned up the area and replaced with a TIP 102. No go - entire row still out.

I ground the metal tab of Q73 during test and the entire row lights up. I also connected another row (Pin 1 of CN5) to this row (Pin 2) and the entire row lights up in test. This leads me to conclude the Q73 is fine. I checked the ceramic resistor to make sure it was on the board and had continuity throughout per a guide's recommendation.

According to the same guides my next step is the Q82 which is a 2N5060 (NTE5400) silicone controlled rectifier or the PIA. I don't have any of these in my stash but I can order some.

Is there anything else simple I'm missing here given the troubleshooting I listed above? I don't believe it is anything else downstream right given the row lights up when jumpered to another row?

So I do have 2N5064 on hand because Great Plains Electronics sold them to me as the substitute for the 2N5060 which I must have needed for another project. Installed that without any change.

Yes thank you I do have continuity there. Doing further tinkering tonight I did notice two additional things:

1. The 7406 associated with the lamp return has a short between pin 7-8. The other 7406 near it does not have this same short. I think this may be the problem.

2. D9 was open - not working at all.

I replaced D9 and no change (but still see pin 8 open to ground on the 7406). My next best guess is the 7406 needs replacing but I do not have one. Unless someone thinks I'm on the wrong track I'll plan to cut it out and install a socket (which I have) and wait for the part to come in. I'm wondering if something took out this entire line (the transistor, diode, scr, and 7406).

Just linking and archiving in case future people read this thread.

Very helpful info here:
https://pinside.com/pinball/forum/topic/7406-inverter-test#post-1017085

Further follow up...

I installed a socket and replaced the 7406 located at F-12 (F 12). This is the one that was shorted. All lights appear to now be working properly. I had two lights stuck on but realized after that the lights over the in-lanes ("Lite Dock and Lite Adv X") are tied to GI and not controlled so they are operating normally.

I have noticed if the game runs for a bit that a few of the controlled lights stop working in attract or test mode. If I push on the connector they work again so I am hoping this gets resolved when I replace the IDC connectors and evaluate the headers.

NVRAM and some other parts (flipper rebuild) arrive today. My ground braid behind the DMD is broken and I'm hoping fixing that helps with the hum. I know the DE/Sega games are loud but right now it is too loud.

I'll update this thread if I discover anything else on the board that I had to fix related to the lights worth documenting for future readers.

This will be my last and final post as I consider my issue resolved. I replaced the applicable connectors (in this case CN 6 and CN7) with new molex connectors. These were original to the game I believe as it still had the weak IDC ones installed. That resolved the remaining issues with the lights.

All lights work as normal.

In conclusion - Row 2 was out and when a Q73 replacement did not resolve the problem I ultimately traced it to a faulty 7406 located at F-12 (F 12) and an open D9. Residual light outages were the result of old connectors on the board which were replaced. Everything appears to be working normally now on the controlled lights.

Glad my old thread may have helped out. In my case the 7406 was shorted...