The tape fix is the same regardless of the particular opto, it is putting tape over the lower part of the opto or hole in the ball guide - this fix stops air balls going undetected. The issue is that a fast moving ball can often have some air and while the ball breaks the top of the opto beam, the opto receiver still detects the bottom of the beam and hence the switch is not activated. By covering the lower part of the opto, means that only the top part of the beam needs to be broken for the switch to be activated, and therefore fast and slow balls are detected

I just had a similar issue but it was the transmitter half of the opto that was out. I knew even before taking the trex out since the red light in his mouth was no longer lit.

Symptoms were that all trex modes were starting on ramp entry even though the setting for “start trex mode on ramp entry” was set to NO.

No idea why the wire got cut so cleanly but easy enough fix. Took the opportunity to install my lior Trex while I had the mech apart. No issues with installation or gameplay. Looks awesome!

Also put back the lower jaw screws that fell out over the last 2+ years Ikve had the game lol.
2C90FD04-D592-4BCA-BA84-8B879E13B84A (resized).jpegE0989503-9435-46F1-AB9A-F5DE82CB304B (resized).jpeg

I have the same thing on mine. Light in mouth no longer lit and all modes start on ramp entry. I have the replacement opto to put in but I haven't done it yet because my T-Rex is really nicely dialed in for catching the ball and I don't know if it's a big hassle to dial it back in after taking it off for the repair. After you put yours back in was it tough to dial it back in to catch consistently?

Let me know how you go with yours, and then I'll do mine (same issue) LOL

What's a 1 owner LE with 300 plays, stern topper and stern shooter rod worth these days?

If you're selling, about $2K. If your buying, about $15K.

Removing the mech was the reason I hadn’t installed the Lior head yet. Game has about 3000 plays. I’ve owned it since Oct 2019. Never any issue with the T-Rex.

However it was so simple essentially 4 screws and 1 C-clip. The electrical connections all have different connector types so no chance of messing it up.

No adjustments were necessary even with the new head.

You tell us?

My only issue is the left orbit.. 1st skill shot..advance paddock etc. 50% miss. I tried the washer fix but think the washers were too thin... went bought some nylon ones at size recommended... will try today. Not sure how to get tape to that location.....

So happy I finally got my first MXV skill shot last night. Happened so fast I almost didn’t even realize it. Glad I was logged into my IC for the achievement because I don’t expect it’ll happen again any time soon lol.

I was able to do it without removing anything. I just used two flathead screwdrivers and a small sliver of black electrical tape to do it. Put the tape 1/2 stuck to one of the screwdrivers and use that screwdriver with the tape on it to move the tape into position (so 1/2 of the sticky side of the tape will be exposed to the guide rail where you want to stick the tape).

Then use the 2nd screwdriver to press on the exposed side of the tape and stick it to the rail on one side of the opto hole. Hold that screwdriver against the tape on the rail to keep it in place while you twist to unstick the first screwdriver off the tape, then press that remaining part of the tape against the rail on the other side of the opto hole.

Here's a pic I just took as sort of a historical re-enactment of how I did it.

18BD08B5-2827-4680-8D23-319B057D54C0 (resized).jpeg

Pic? please..... never mind...it just showed up Thks!

Good to hear! I'm going to replace the opto. Thanks!

I think this is the wrong opto. The one I am having issues with it the trex ramp opto...attached to the plastic ramp behind the backboard...?

Oh, sorry. Your post said your only issue is left orbit so I was thinking it was that opto.

My bad I should have specified. I even added the washers to the orbit opto...and started digging in.. now how to fix that one..??. wonder if washers would fix it as well... cant get tape to it very easy....

This post may have what you're looking for...
https://pinside.com/pinball/forum/topic/welcome-to-the-jurassic-park-le-club/page/62#post-5321884

1 side armor left it looks like.
https://www.classicgamerooms.com/pinball-parts/stern-jurassic-park-pinball-armor-kit-detail.html

I contacted them the other day they do not have them in stock and he doesn't know when he will be getting them.

False advertising

He thought they had it but he went and checked and said they are awaiting stock.

So what opto scores the skill shot and advance paddock... that low one....or the one in the back...???

Back one

Maybe try some washers like recommend before.?.. I dont see a real adjustment... but its hard to see...

Just be aware that this post is associated with the original left ramp protector that does not have the opto hole. Given the airball issues with the ramp and T-Rex catching the ball, Stern modified the ramp protector to include a raised opto hole, effectively doing what the tape fix did.

The "made ramp" opto in question is a different opto switch at the back of the ramp behind the backboard

Mine is the last build I think... got it Aug I think... i do have a opto behind the backboard. any inputs on adjustment...?

You can't raise the optos due to the ramp design (see the below pic). People have had success by adjusting the alignment of the optos, as well as taping around the hole and drilling the hole in the ramp slightly larger - I suspect that there might be some refraction occurring on the edge of the hole and hence why these different approaches have worked.

https://pinside.com/pinball/forum/topic/jurassic-park-stern-2019-owners-club-welcome-to-jurassic-park/page/212#post-6309369
https://pinside.com/pinball/forum/topic/jurassic-park-stern-2019-owners-club-welcome-to-jurassic-park/page/186#post-6089559

JP T-Rex ramp back opto (resized).jpg

Hi All,
Today my lower left flipper started to stick. If I hit the flipper button it flips and stays in the up position until the ball hits it or sometimes after a bit it drops on on it's own. With the game off or a game not in progress if i manually push the flipper up it returns to the lowered position with no issue. Does this sound like a coil stop issue? I had ordered coil stops when i first bought the game 7 months ago from advice of others to always have some on hand. Before i swap it out just wanted to see if people thought it was that or possibly something else. I am little new to the hobby so just wanted to check.
Thanks!

sound like the spring is broken/unhooked. Just prop up the playfield and compare to the other side if you are unsure.

If the spring is ok then it's likely the coil stop.

Thanks the spring looked normal, I switched out the coil stop and everything's working again thanks for your help, just wanted to make sure there was nothing else to check before switching the coil stop

Just a heads-up, Karl DeAngelo (iepinball) is streaming Jurassic Park for the next few hours and giving away some pinmonk stuff (quiet fan kits/t shirts) to viewers during the stream (and every stream in Jan).

https://www.twitch.tv/iepinball

Tonight the contest is to guess how many insider achievements he'll get on a clean JP Premium account. There's a link to the google form you sign up on in the stream. Winner gets a quiet fan kit (spike or spooky). Runner up a pinmonk T-shirt. Type !Contest in twitch chat for his stream to get a link to the contest form and sign up within the first 30 minutes of the stream.

Oh, and Cone of Shame is back as a reward that can be purchased.

Bummed I missed this.

The stream's still there and is pretty interesting.

Karl/IEPinball is doing live quiet fan and t-shirt giveaways all month on every twitch stream he does in Jan, and mixing it up so the way to win is different and not the same each stream. He usually streams starting at 6 or 7pm and posts to his facebook/twitter when he's doing it. You have at least 20 more chances to win (10 more streams x 2 prizes per).

I will be watching!

Karl/IEPinball is streaming Jurassic Park Prem starting in the next few minutes and will be giving away a quiet fan kit for Spike or Spooky (winner choice) and a T-shirt during the stream. Entries are from now until 8:10 winners announced later in the stream.

Type "!contest" (minus quotes) in the twitch chat to get the link to the entry form.

https://www.twitch.tv/iepinball

Well I loosened the screws....moved it a bit and cleaned it....and so far have not missed a read yet....

Can someone post the bias settings for the TREX adjustments? The last three options in the adjustment menus. Thank you in advance.

I think this is going to vary by machine, but I can get you mine tonight.

Here are mine. I found it catches the ball better if the mouth is slightly closer to the left side of the ramp. Yours may or may not be the same.

Left 0
Middle -5
Right 0

Karl DeAngelo at IEPinball is streaming JP Prem tonight starting at 7pm pacific:

https://twitter.com/iepinball/status/1481300827054563332

...he's also giving away more pinmonk quiet power supply fans and t-shirts. He changes the contest night to night, but basically just type "!contest" in the twitch chat (without the quotes) to get the link to the contest form and enter in the first 30 minutes of the stream.

https://www.twitch.tv/iepinball

(entries close at 7:30PST. Tonight's contest is easy, just YES/NO he reaches Escape Nublar)

EDIT: Very intense end. Karl made completed the escape, so the answer to the contest was YES. dent123 lost out on a prize at the end - wasn't in the chat to collect. Went to the next on the list instead.

Freebird did you ever look into this further? After playing today, I noticed my T-Rex doing the same thing. Sometimes after the intro roar, the jaw stays open. During game play the jaw will sometimes stay open at times. Also, once T-Rex Multiball starts, T-Rex tries to do the chomp but the jaw stays open a little and the ball falls out of his mouth on the left side. The ball is supposed to stay in the mouth longer for sure. I have the same binding if I open the jaw fully by hand but also wonder if the magnet is not working as it should or is it just the lower jaw not closing like it should.

I've encountered the same problem. I think the jaw mech is making contact with the upper inside of the rubber body. I think it needs more clearance but I haven't figured out a solution. At first I thought it was a coil issue or a sensor issue, but I do think it's a jaw binding issue at this point.

I temporarily gave up the movie assets and call out to get my insider achievement point. Finally got my Insider connected scanner today and installed it on the coin door.

4032B5CB-623A-4AD0-9C6E-F3B8E197DA50 (resized).jpeg

Let me know if you figure anything out. It was fine for a few months but just started doing it.

It would be interesting to see the inside of the coin door and how you mounted it. More pics and details please.

Thanks!

Just remember not to go commando in white shorts

RefugeNate, I have the exact same situation you describe - sometimes the jaw stays open during intro roar, sometimes during game play, etc. I did confirm that it is just the jaw sticking and not a magnet issue. I also confirmed that in my case, the sticking is related to temperature. My machine is in a room that can get kind of cold, sometimes down to 57 degrees or so. If I come in, turn on the machine and do a jaw open diagnostic, it will stick open - maybe for a second or two, or maybe for quite a while. If I leave the machine on for an hour or two and add some heat to the room, it works fine. I bet your magnet is working fine. The jaw and the magnet work together to get the chomping action. If the jaw sticks open even briefly during the chomp or just after he grabs it and swings his head, the ball comes out when the magnet releases even if it's not supposed to. I still plan on taking my t-rex out and figuring out what exactly is binding.

Can anyone tell me how to decrease the movement of the Trex to the right (players left). Thanks in advance.

As this is my first post my apologies if this question has been already covered or if I am posting in the wrong spot.

I am trying to remove the hinge on right side of my JP Premium so that I can send it out for powder coating (LE Green). But, I can't see how to get to the second bolt. Do I remove the screws on the metal box? Is there a trick? Thanks, Greg

JP Prem Hinge outside right (resized).jpg

JP Prem Right Inside hinge bolt (resized).jpg

This is a great observation. Mine started acting up when the temps dropped. I think the rubber is constricting just enough to cause hang ups.