A CL find with the "My son had it working but didn't play it much." info ha. Have only cleaned/fixed some older style machines so this is my first with a small LCD screen.

Not sure what frame this is and haven't found a manual. Boots and LCD plays animation of slots and airplane flying. Shooter does not start and only lcd and flashing red lights on front. Has some type of bypass dongle plugged in. Has 5 led numbered lights that light up when turn it on. after cycling on boot up lights 4 and 5 stay on. 2 push buttons under these LEDs. If remove dongle no lights. Thought maybe wasn't registering hopper full but examined mini-switch up there and looks ok. Cleared ballruns, have not seen motor assisted section activate but did clear it. Any ideas or know a similar machine i can read through troubleshooting with? Would love to get it working to bring in for my HS students to check out!