Did you lift the playfield and look at the wiring to the coil.

To test the coils, READ THE MANUAL, Page 30...it's available at ipdb if you don't have a hard copy...

If you got to that test mode then you should be able to find the one your looking for. There is a mode that lets you select the coiil you want and fire it when you want. The mode is called Coil Select or something similar and you use the flippers to select the coil you want. Which is why Tom is telling you to look in the manual. You can find every option available to you in the service menu, including what that option does, and how to navigate it. As he said, the manual is available for free at ipdb.

http://mirror2.ipdb.org/files/1343/Data_East_1993_Jurassic_Park_Manual.pdf

Foz, if you got to the coil cycle test then you're in the right place. Just navigate further along the Diagnostic menu, past the T-Rex diagnostics and I think past the light tests and you get to the coil test. From memory the first test mode cycles the coils and the mode immediately after this is the Coil Test where you use the flipper buttons to select the coil and the Start button to activate it.

Perhaps you missed it by whizzing right past it. Navigate through the Diagnostic modes slowly and you'll find it

Have you checked that the trough VUK switch on this coil is sitting under the seat correctly? After cleaning the subway VUK a month back I forgot to place the switch wire under the seat and it wasn't activating when a ball sat on it. If it's positioned correctly then try the switch test, and see if this switch is working OK.

You have to use the Start button to navigate into the diagnostics, you cannot just use the coin door buttons.

Huh … I just use the coin door buttons. Start button toggles the options that are navigated to using the coin door buttons.

On startup with the white button depressed, pressing the green button enters Diagnostic mode, and each press of the green button moves to the next mode. Diagnostic mode navigation is one-way only.

With the white button not depressed, pressing the green button enters Audits & Adjustments mode. When in this mode, each press of the green button while the white button isn't depressed moves to the next mode. Each press of the green button while the white button is depressed moves to the previous mode.

So the white button acts as a forward/backward navigation toggle but only in Audits and Adjustments. Diagnostic mode goes only forwards regardless of whether or not the white button is depressed or not.

Perhaps this behaviour changed with newer ROMs, mine is still on the stock ROM.