I'm sure others may have better advice than I do (I don't have an MMR), but my first suggestion is to unplug the mods first.

Rule #1 of troubleshooting...undo anything that's been changed.

LTG would probably recommend opening a tech ticket. Just guessing

Theres a location in Michigan having a similar issue that I heard about recently.

Service tickets go to Chicago Gaming.

Also had experienced a similar issue on mine. I opened up the game followed the wires coming off of the flipper coil to a connector that attaches to the board underneath the playfield. Turns out the connector made its way loose somehow and wasn't fully seated. Unplugged it, then plugged it back in and it was back to pinball. Has worked fine since. It's worth a look.

In addition to checking the wiring and making sure all connectors are seated, be sure to check that the solenoid driver board (coils from flippers plug directly into this board) is firmly seated into the main board. The little board is a socketed board with 4 screws. You can unscrew it and reseat it.

Hope it is up and running soon.

Also check the line box! The HV connectors going into this box are sometimes not properly seated from the factory.

http://www.chicago-gaming.com/ Please always open a ticket, so they can track issues.

From your description you have a loose connector somewhere.

Next time they go dead, please go to Tests - Switch Edge, and push both flipper buttons. Then you'll know which connectors to look into. Flipper button opto boards, or flipper coils.

LTG : )