I just got a Jurassic Park this week. Prior to grabbing it the previous owner said it was working fine. I was not able to try it first. Game boots fine and everything works besides the lower right flipper. The flipper board has been switched to a rottendog. Originally the dip switches were set wrong so I set them correctly.

The right lower coil will fire when button is pressed, flipper goes up and stays up then burn the fuse on the flipper board.

The button switch was wired backwards (upper flipper on first button) so I swapped that. Coil diode tested fine but I replaced anyways. I don't see anything out of the ordinary near the flipper. Solder on lugs is a bit messy but seems intact. EOS switch is closed and appears to be working (LED from button only displays when the switch is closed). Tested the transistors on the flipper board and they all read about the same so I don't think one is burned and the way I read the schematic they should be behind the fuse anyways... There are some hacky repairs on the power board but All TP voltages look fine... Help Pinside!!!

Stumped on this one... Did a deep dive on the flipper board and can't find any flags that something is wrong with the transistors... Is there anything on the power board or MPU that drives flippers on these data east games? Noticed both right upper and lower coils are not the correct # per the manual so may just try swapping them out for the correct coils with fresh diodes and see if that changes anything.

Positive that the switch is definitely good as the flipper board has the led showing its receiving the signal. I will double check the shaker board and report back. I tested all the flipper board fuses and back box fuses but not sure I tested the shaker board! Thanks for the tip on linking to the owner thread. I gave that a shot as well!

Turns out both upper and lower right coils were wrong and the flipper board was bad. Switched to correct coils, replaced flipper board and we are up and running.