Post your question here https://pinside.com/pinball/forum/topic/jurassic-park-club .They know all about TRex issues

I have a nice used working perfect t rex motor and gearbox , if needed. Make fair offer

extinct

Sold my DE Jurassic Park 2 years ago. Best to ask here https://pinside.com/pinball/forum/topic/jurassic-park-club

With that said, the T-Rex should move side to side, up and down, open and close it's mouth, and eat the ball. Here is a time-stamped video from my sales video 2 years ago.

T-REX motor repair can be complicated. I'm going to guess between $50 and $400 U.S. to fix depending on parts needed and repair skills. Good luck!

There is a setting to shut off the movement of left and right. Check in the settings to see if it’s shut off. It looks like Rex isn’t closing the switches that can also be tested in the settings. You would just adjust the switch gap or where they are placed in the wood.

This will also help in your quest... The "theory of t-rex"
http://www.marcospecialties.com/pinball-parts-blog/wp-content/uploads/2014/12/039A_SB.pdf

Also...I don't think this is your issue, but the relay boards for the trex under the playfield are known to suffer from cold solder joints and often need to be reflowed.

Good luck.

If JP is going to be a long term pin for you, I highly recommend getting this motor and gearbox.

Hopefully it is just the motion that's turned off in the settings...or a loose wire or cold solder. If not, T-rex motor repair is costly and time consuming. You would be better off with a replacement.