I have a TZ that started acting strange tonight. It's not giving any errors, boots and plays normally, but randomly during a game the DMD will go to rolling vertical lines and the a couple flashers and gi lights will lock on, the music continues like nothing happened and the flippers stop.. The game basically freezes and the coils stop responding. You cannot reset it with the coin door or enter test mode, it doesn't respond at all. Almost as if there is a power issue or something?

After shutting off the game down for 20 secs or so, upon turning back on it will boot normally like nothing happened (normal DMD with no errors), but it happens again during the game on the 2nd ball usually. Any ideas or thoughts? I will get my multimeter and check all the suspect areas later tonight.

When I tested it tonight, after the flippers stopped and dmd started the rolling lines, it started to smoke from under the PF and you could smell an electrical burn so I immediately shut it off. I cant trace the issue, it seems like it was smoking from the area circled. The 3 red lights on the mpu board went off once the problem started.

There was a tan resistor laying inside the back box loose on the left side, I'm trying to figure out where it might have came from.

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Actually it was a resistor my mistake. Here it is.

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Thanks Rob I will check that. Heres a vid I took just before the last time I checked it (before my last post). What do you think? I checked under the playfield and the coils and connections seemed fine but it was definitely smoking.

It's obvious I'm not very technical. I can replace coils, solder wires and do basic repairs but usually get someone else to help with board issues. I have had luck with help on here with most minor repairs I couldn't sort, but may be over my head with this one. I like working on these just wish I had more knowledge!

Thanks. Do you think it's ok to do this and test after the smoking from underneath?

Thanks, I reseated and checked those connectors, game functioned normal no issues for about 3 balls then mpu went haywire. Evidently the under playfield smoking wasnt any lasting issue since it was shut off in time.

This game has some pretty serious hacks (not from me) someone really went crazy with splicing. Not sure if that has a hand in it.

I have a friend a few hrs away picking up a couple games from me in a couple weeks that I'm selling, I'll ask him to bring his tools and see if we can get to the bottom of it if I cant diagnose it by then. It appears the mpu area is where the problem lays with what help I've received here, unless I'm missing something. Game worked fine until I lifted playfield to replace shooter rod the other night, played a few games than it went batty.

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Well I got the problem fixed today. I ordered a kahr daughter board at the recommendation of someone, and when I went to remove J210 to install the board, I noticed it already had one! I went ahead installed the new one and the game functions fine now. No MPU issues at all and I tested it for about 20 minutes.

Guess these little boards go bad after 5 years or so (it was dated 2014).

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interesting. what did you do to remedy your underlying issue? these boards are just a patch with the power issues still present of course.

Thanks. I wasnt blaming robs board, I was highlighting the area that corrected the area (at least short term) but I see how that could be misconstrued and edited the title. I'll reach out to him for input.