The URL below shows a JP with the diode mounted remotely.

Gord

https://pinside.com/pinball/forum/topic/jurassic-park-club/page/4#post-1939477

My JP is having an issue. The coil that kicks balls into the shooter lane seems to work fine for several games and then ends up getting stuck. The problem is especially evident during multiball. I'm having trouble tracking down the issue and I thought it might be the vertical switch on the right of the ball trough but I've replaced it twice and I'm still having the problem. Anyone else have any recommendations to try? I have a video demonstrating the issue:

I had the same problem. I solved it replacing the coil.

Control room scoop diode is a service bulletin, so it should be on the switch itself unless someone moved it to a remote location.
I just uploaded a couple more service bulletins to my facebook group. https://www.facebook.com/groups/JurassicParkPinballOwners/

It's service bulletin #43. (Thanks Ingo for uploading)

After the service bulletin came out, they started mounting the diodes remotely at the factory, as seen a couple posts above.

Mine are connected to GI. Green and Green + White line.

Funny my flashers weren't working up there but then it looks like mine never had a topper either. Screw holes are pre-drilled but never screwed into. On my machine the flashers didn't have bulbs in side the caps. Guess this is how the game came? So... dumb question but do you have bulbs under the other caps?

Remove cover and check coil #16 Q23 trough lockout.
This solenoid is supposed to release one ball at a time
onto the eject VUK. It could be gummed up.

Mine light up all the time and flash some times. I dont have any more details at the moment.

To clarify the three lamps on top are GI lamps the circuit is part of the
back box lighting.
1) If not lit, check for bad lamps and or broken continuity.
2) If back box and playfield GI is lit, then the top three lamps should
--- be lit.

Thanks for all the suggestions on the T-Rex not eating the ball issue I'm having - definitely appreciate the thoughts and help. Spent some time with the machine did worked through the diagnostic checks recommended and while I haven't gotten to the final solution yet, it seems like I've definitely eliminated quite of few of the other potential issues sources (which is a win for sure). I did check the main cable conduit to him and all seems good with no cracking of the wires - so I think I'm good there. I also ran the T-Rex diagnostics and it looks like he's doing everything he's supposed to (all the switches check-out - top/bottom/center/left/right and I can even get him to "chomp" when he's in the up position (all the switches on the diagnostic menu check out good). The issue still remains that his jaw doesn't "close" around the ball when he's in the full down position in game mode (or diagnostics mode for that matter) - but he does everything else perfect. In the diagnostics mode, I did try the trigger/jaw test when he was fully "down" but nothing happened, but I don't know if that's really a diagnostic test protocol or not (in the down position).

When he does go down to pick up the ball, is his jaw supposed to "close" around the ball in a separate action trigger or is this more of a "friction" action where the jaws simply envelope the ball and then eat/dispose of it when it "chomps" when it's fully up? If it's a "friction" issue, was thinking may I need to tighten up the jaw or something similar?

Thanks again for any thoughts or past experiences - think I'm getting close!

Mine was having this same issue and I ended up having to replace the black wire that runs to TREX. It's a known problem that I found in a post somewhere but my issue was what you described - chomps fine when vertical, won't chomp when horizontal. Something about a black wire rubbing wrong or not being long enough, don't remember exactly the issue, but replaced the wire and it works fine now. Sorry for the really crappy description. I'm sure a few pinside searches will turn up a much more thorough solution.

The TREX "closes" around the ball, brings it up vertical and it falls into the subway. It doesn't "hold" the ball in it's teeth, just grabs it into it's mouth.

Your cable wire is broken at the "L" bend.

Thanks--will dig deeper into it and take a closer look for the black wire issue--certainly appreciate the help and sounds like the exact same issue so hopefully same solution too!

YPURCHN or VEC-TOR - can you clarify or even maybe send me a pick of the black wire connect/general location when you get a second? Not at the machine right now, but remember seeing a bundled/sheath of wires that leads to the T-Rex from the playfield and trying to confirm if the black wire will be in this (and I'll need to remove the sheath) or if it's separate from this bundle.

Thanks again for all the help - appreciate it!

There are 2 wires going to the coil on the back of the t-rex, probably sheathed. They should be exposed to where you can see the color going to each lead on the coil. Make a note of which color goes on which lead in relation to the diode (banded side or not) and look where they connect under the PF (I can't quite remember where they terminate off hand). Replace the entire sheath with both wires. The break could be in either wire, so just replace it all.

Hey all. I wanted to thank you for the assistance with the T-Rex jaw mounting bracket. I replaced the parts and now we are back in business.

I do have a new issue with some switches. All 7 of the CN8-5 Switch column are not registering during diagnostics and they are all on the same circuit. Control Room and Bunker stopped working, three nearby targets (pics) and the ramp switches.

I've tested all of the fuses I can find inside the cabinet and in the back box but all have continuity. The CN8 connector that attaches to the CPU looks ok as well. Am I missing some fuses attached to the playfield?

Any pointers would be appreciated!

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My instruction card refers to the Computer Room instead of the Control Room as starting the different modes - Stampede, etc. Has anyone else noticed that? I am pretty sure I have an original Instruction card.

dearliza98 - I've encountered this a few times. First thing to check is the right ramp exit switch. Pulling the play field in and out always runs the risk of hitting this switch with the way it mounts to the back.

If that looks good, you'll want to follow that wire (green/black) from switch to switch. If none of those switches are registering, chances are it came loose at one of those switch points. The center scoop switch is notorious for shaking the wire loose.

Good luck!

tjprice222 thank you for the help! I will check it out tonight. I noticed that switch on the top/back of the ramp. I really hope it's something simple like that.

tjprice222 well I spent a couple hours last night trying to track down the source of the switch column failure. I got the switches to register a couple of times but it was random like a wire is loose but I can't figure it out.

I'm wondering, do you know if there is a way to isolate the issue to a particular switch? I have a DMM but not sure what exactly to do. Thanks for the help!

OK I need help finding some of the parts.

Where do I find the large chip PN: F6808P

Also while I am asking, how do I figure out the part numbers of the resistors, resistor packs, and cap on this board?

In the picture I circled C94, RA4 and another one.

Thanks again

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DearLiza - Did you replace the IDT connector? Also, there appears to be corrosion on your circuit board. Did the batteries leak at some time? The corrosion should be cleaned up, as it will continue to grow and cause more problems in the future.

RA 4 is a resistor array - I doubt that it's bad.

Great Plains Electronics is a good source.

Billc479 I think your response was actually for C65Mustang but appreciate the sense of community regardless!

+1 for Great Plains. They are a great place to buy any type of electronics for board repair.

Yes I am working to remove all the corrosion but wanted to replace some parts as well since the corrosion has crept up the legs of some chips, cap, resistors, diodes, and transistors on the board. That main large chip is really what I am worried about.

That is a 6808 processor available at Marco or others.

http://www.marcospecialties.com/pinball-parts/6808

does it need any special programming or can I just buy a new one and install it straight out of the box?

Buy and install out of box.

Correct, and remember the semi circle notch shown on the left end of yours identifies how the chip is oriented, so put the replacement in with the semi circle or notch on the same end.

You can also see the smaller 14 pin chips above it have a similar notch at the end to show the orientation.

Nice!

Dang it. I have an issue to track down. Was playing yesterday, and right after the Trex ate the ball, the game thought it was tripped by the slam tilt. Pretty sure it has to be a short, right? Time to break out the schematics I guess.

check your coindoor tilt switch
just in case

I recently picked up a JP that has a shaker. Did they originally come with one? Also, I'm thinking about LEDing it but notice lots of fade going on in the GI. Has anyone had any issue with that?

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Yes, JP did originally come with a shaker motor. When the T-Rex picks up the ball the shaker motor does its thing. If the GI is fading it sounds like you may need to replace some oxidized GI connectors and also re-pin the appropriate male headers on the power driver board.

Gord

Definitely seems like a controlled dimming at points. Maybe I need to play it more, I could be wrong.

Nice work, can't wait to see the 3D backglass. I never really had an issue with the backglass; but if you could create an alternative payfield; I'd be interested.

I don't recall dimming, other than turning off/on at the start of multiball and such. More likely the GI connector is failing.

Yeah no dimming I was wrong. Damn this game rocks!

alternative playfield? now that would be ambitious

There is a square molex connector that connects the two switches and light from the gun to the cabinet. By disconnecting the molex connector, removing the four bolts you can unscrew the gun into two halves. You will see the bulb once you separate the two. My problem is I can't get my light in the gun to turn on. It is in parallel with the one on the playfield but I have not found where the wire break is. Anybody know of a common break point? Mine was a #555 bulb.

The light socket under my 2 ball play area on my playfield is corroded so bad the light will barely come on. What is a good replacement for this light socket? I looked on http://www.marcospecialties.com but I was unsure of which one was the exact replacement option.

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Added over 7 years ago: Forgot that I chose not to change (1) #44/47 bulb that is under the subway...

Also their are (7) #455 in the backbox in the bottom row that should lower the #44/47 by (7)

Otherwise matches what I got.

Hello all, just purchased my first JP

Mostly joking. I'm just not a fan of Markus Rothkranz's playfield art style.

Just curious to know how many of you have a topper installed. Mine does not have a topper. Was the game originally sold with a topper or was it an add on?

I always assumed they came with one, but never asked. My topper is sitting in a box because I need to extend my ceiling before I can put it on lol. I have determined the best compromise would be to cut the legs down and add a recess to the ceiling. There is no reason to use logic and just move the machine lol

I've owned the game twice and both included a topper. I've assumed that many have simply been broken or lost.

Hi sagejr,

JP was originally sold with the topper. I purchased my JP from the original owner and he told me that the game came with the topper when he purchased it NIB from the local distributor (Game Exchange) in 1993.

Gord

Can anyone help point me in the right direction for this under playfield lamp socket?