Picked up a Congo recently and just got it setup but it's having some boot up issues. When turning on the machine with the coin door open the right flipper is sometimes activated, dmd is scrambled and only a few lights turn on. Four bongs are heard then it resets and the same cycle is repeated. With the door closed it sounds like some solenoids are activated and the GI will light up for a few seconds then the machine resets.

I saw that the F103 fuse was blown on the driver board so I replaced it with a 4A Slow Blow. New fuse was blown again on F103 when I turned it back on.

It was working when I bought it. Has Rottendog A/V and Power Driver boards. It is a reimport game. Are there some things I can check to narrow down the problem? Thanks for any help with this. Pics of the CPU, A/V, and Driver boards when the machine is on-

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Thank you for the suggestions PinballManiac40
I reseated all ribbon connectors on both ends and pressed on all the IC sockets. The driver board diodes are all consistently around .47v

No change when powering on after reseating but the F103 fuse didn't blow on power up this time so that's good ha.

My fault that was with the door open. Just tried it with the coin door closed and it did indeed blow the fuse. Right flipper energized as before.

Just tested those four and all read around .46v

Sorry I'm new to using a DMM, is this the correct setting? I have tested the transistors with the red probe on each metal tab and the black probe on the metal grounding plate. All are reading as OL.

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They do read less than 1 if I touch the leads together.

This one came from a retail shop and it was working there before I brought it home. They didn't mention anything and it wasn't until I got it set up at home the problems started. I found some hacks under the playfield with the 10 opto board I'll have to undo at some point, wondering if that could have anything to do with it.

DMD still not displaying right and same startup behavior as in the first post. I could record a video if it would help. I appreciate you taking the time to help with this, I'm sure it's not easy trying to diagnose an issue without being able to see the machine in person.

Checked this today. Replaced the fuse, closed coin door and powered on. All lights on driver board are lit, looks like the 50 volt is not as bright as the others though. Every four seconds or so the dmd flashes (scrambled) and the right flipper as well as the auto launcher and kickback are activated. When that happens the 50 volt led will pulse. Fuse did not blow this time even with the coin door closed.

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I have two diodes on the right flipper, one reads 0.001v and the other is 0.065V. I get the same readings on the left flipper diodes.

The left slingshot plunger feels pretty sticky and doesn't move smoothly so I'll get that cleaned up. Never done any board work but should that be the next step to replace the transistor and diodes on the board? Thanks PinballManiac40 and freddy for the advice!

Not sure if I'm testing this correctly, machine off and multimeter is set to ohms, probes on right and middle coil lugs I'm getting a reading of 004 on these. If I test the left and middle lugs I get a reading of 126. Same reading on both coils whether the flipper is up or not.

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With those disconnected the right flipper is energized for a second then drops, dmd also comes on for a second still scrambled. This cycle repeats a few times then I hear a single bong tone before it cycles again.

Thanks for the info on the ohm readings, glad to know those are correct.

Issue solved. Sent the driver and MPU to Chris Hibler, turned out to be a bad ASIC chip. Game now boots and plays but I see there is an error with the soundboard so will have to look in to that. Thanks for all the help!