I am still figuring out stuff on my JP, so here is a very basic question. Is the shooter rod supposed to have a rubber tip? Mine came without one, and the rod itself is plastic. I bought a set of replacement rubbers for the game and it came with a shooter tip, but the rod guide is too narrow for the rubber to fit.

Great, thanks for confirmation that what is there is correct.

That really does look terrific. Where did you get the image?

Smerff, Matt - That image is there in the back! Clearly needs some lighting.

This looks great. I'd love one - what would be the total cost with lights?

Question about diodes for ball trough -
I was having intermittent registering of all 6 balls, and now it is always missing one. The problem is clearly one of the microswitches, so I will change it out along with another one that was replaced by a prior owner, but is not quite the right one. I will use new diodes, but I cannot find the diode type for those - can anyone tell me what diode to get? Thanks for your help!

Rock914 - thanks. Looking forward to getting my JP back on line and looking sharp with your acrylic backing.

Hi, what is the new display rom? I thought the new code from Chad was just the cpu.

That is the best idea, could be a wire came off, too. But if you do need to buy it, the switch is 500-5442-01, and Marco has it - http://www.marcospecialties.com/pinball-parts/180-5057-00

Below are pix from my JP, and the bunker looks like yours (except for the hot glue!) but the control room does not have a diode and has two additional wires. Mine does work - do you have a couple of loose wires in the vicinity? Or maybe mine is hacked?

bunker switch.JPG
control room switch.JPG

For the control room, do you have the same three white wires as mine and I am just missing the diode? Maybe this explains why sometimes my control room switch doesn't register the ball. Perhaps, to followup phollibone's request, someone could post yet another picture of this switch? Thanks.

Wow, thanks. So it is obvious which wires are the hack, but what the heck should I do with them once disconnected from the switch?

markp99 and Pimp77 - you win the prize! I traced it and found exactly what you described. Those two extra wires off the switch go to this connector with the diode. The two wires on the right get buried in the mass of wires that pass by, so not sure how to trace those. Since this uses wires with what appear to be original markings, do you think this might be an original setup and not a hack?

Off_switch_diode.jpg

Thanks for all this information, glad to know I have the "upgrade".

I switched out the yellow saucer on mine for the red from Marco and used a red 2 SMD flex from Comet: 2 SMD 6.3V AC/DC SUPREME BRIGHTNESS 5050 SUPER FLEX NON-GHOSTING

It is a really bright and intense red, and looks very cool when the pinball is sitting in the lit saucer when it activates tri-ball.

My TREX all of a sudden stopped chomping the ball when it bends down. When it goes through startup diagnostics, the jaw chomps. When I access it through the diagnostics menu, the jaw chomps when I pull the trigger. I thought it might be a switch that is activated when it lowers, but did not see one for chomping in the switch matrix.

I looked underneath, and did not see anything that is obvious, like a hanging wire. Could someone suggest where in particular I would look for the fix? Here is a pix of the mechanism, if that is useful Thanks for your help!

TREX_controls_(resized).JPG

Thanks for info. I tried to bend the switch, and then activate the Rex. Now that I am looking closer at it, what I see is happening is that the head starts to move up then the jaw chomps. I clearly remember it used to chomp before moving back up. The jaw appears to also be open more than it used to be, and now rests on the lip of the wood outside the saucer, not in the saucer. However, I don't think it is stuck on the wood, as I can see in a video I took that the head actually moves up a bit before the jaw closes. Could this be a mechanical issue? What controls how far the jaw opens? Thanks again for your help - I would like to know what I am looking for before I start to take the head apart.

I am not sure I understand what "wiring loom" means. Is there a specific replacement part to buy? Also, is there a guide for how to disassemble the Rex? Again, thanks for the help.

Thanks for the help. I have been following the incredible t.rex mod from winteriscoming, and in looking back, I see he posted the installation video which serves as a very clear guide to disassembling it. I will use this to dig in and see what needs to be fixed. Thank you to matt_adams and winteriscoming! I will followup on what I find.

I now realize the clue was in this comment from winteriscoming. When the down switch gets activated, that is when it chomps. The problem is that this switch was not being activated early enough. Likely due to losing sensitivity in the switch. I tried bending the arm up, but then it was closing too early (both the switch and the jaw). I tried putting a rubber on the metal piece that activates the switch to make it larger and activate the switch earlier, and now it works part of the time. No way around it, just have to replace the switch, which means several days wait. Hopefully this will clear up the problem.

I hope the JP club can help me with this problem - I don't know what to do. I was playing as usual, then the game froze up. So, I shut it off. When I turn it on, the shooter rod solenoid fires once, the GI lights come on, and the shaker motor starts hard then gradually runs out of steam. The DMD, if anything is on it, is a few horizontal lines at the bottom.

In reading http://techniek.flipperwinkel.nl/desega/index2.htm, I would guess this is a CPU problem. Looking at the diagnostic LEDs, The PIA and +5V stay on, and the Blanking LED never comes on. The guide diagnostic says: "PIA LED turns ON (and stays on), blanking LED never turns on: EPROM at location 5C and/or 5B is bad." But I have Chad's new code at 5C, so this is not likely the problem. Or is still a possibility?

The techniek site further states: "If the game will still not boot, the most common problem is a dead 6808 (or 6802) CPU at 3D. Either CPU can be used, but the 6808 is largely unavailable (hence the 6802 is used as a replacement). Also a dead 6264 (or 2064C) CMOS RAM at 5D is very common." I have a 6802 at 3D - should I replace this? I have an NVRAM at 5D that I put in last year, and there is no battery damage on the board.

Any other thoughts about how to diagnose or what to check would be greatly appreciated!

Thank you for the suggestions. I will look at both these tomorrow and give an update.

I am finally getting some time to diagnose my ill JP. Taking the above advice, I did find 3 fuses blown -
Power Supply Board: F5 (4A), F1 (7A)
Playfield Power Board (PPB): F9 (4A)

I don't have any 4A fuses, so hope to run out tomorrow to get some (if no luck, can I use 3A ones while I try to diagnose?). But, I see that F9 on the PPB connects to the shaker motor. In case the problem stems from the shaker, how can I take it offline to see if the game runs fine without it?

Looking at the fuses, none are obviously blown, but they certainly do not have continuity. Does anyone have thoughts on how these three blown fuses might be related?

So, because the shaker was running, I unplugged the feeds to it, replaced the fuses, and turned on the game. No fuses blew on the PPB, but F1 and F2 blew. These are in line with the bridge rectifier BR1, and when I tested, one leg was shorted. So, I replaced BR1.

Now the game boots up and will start a game, so that is a major advance. But it is three steps forward and two back. The flipper buttons are now not controlling the flippers, but the raptor and shooter solenoids. I tested all the fuses again, and now F5 on the PPB is blown. This is in line with the BR1. It is hard for me to imagine that both bridge rectifiers, on the PB and PPB, could go at the same time. When I test with my DMM in diode mode, I get the correct value, about 0.47 on all the legs. HOWEVER, this is regardless of whether I have the red or black lead on the + or - terminals. Same reading with either lead. Does this mean that there are voltage drops on BR1 regardless of the diode direction and it has failed, or is it just acting like a normal diode that cannot be tested in circuit?

If it is not BR1, any thoughts on where the problem might be? Thanks!

I'll move this to a new tech thread.

Great job on the replacement! I have the same one broken on mine. Do you a scan of the image you can share? And what type of plastic did you use?

PM sent - thanks!

With all these new sets purchased, there must be a similar amount of old sets needing a home (even with the several comments of those holding on to their old set). I don't think I am the first to make this offer, but if anyone is willing to sell some or all of their old set, I specifically need the plastic behind the upper flipper but will buy the entire old set if preferred - please PM me. Thanks!