Gottlieb logo Steve Kulpa's Joker Poker
Pinball Machine
Gottlieb logo

Gottlieb's Joker Poker is my all-time favorite pinball machine! I first played one while attending college back in the early 80's and fell in love with it right away. I love drop targets, and Joker Poker has a ton of them. When the pinball bug revisited me this year, Joker Poker was one I had to get. Even though I settled for a Bobby Orr Power Play as my first machine, Joker Poker was still on my mind, and still tops on my list.

In March of 2001 I placed a want ad at Mr. Pinball and got a response from a guy in Flordia. He was coming to Knoxville for an auction and said he'd bring the machine with him so I wouldn't have to pay shipping. After I got it home and gave it a good looking over, I realized this machine was in so-so condition. It needed all the circuit boards, a backglass, flipper coils, several new drop targets, and a complete going-over. Plus there was a big gouge in the playfield near the right flipper. I was a little dissapointed at it's condition, but at least I got one. I put it aside for the time being, since my wife will kill me if I don't do some household projects first. Then a little later I found another Joker Poker at a place called Cooper Billiards in Knoxville. It had been sitting in his warehouse for who knows how long. It had a backglass, almost perfect, an excellent playfield, and was only missing the driver PCB and the flipper coils. I got a good deal from Gary Cooper and took the machine home that day. So I started with two machines, with the plan on combining the best of both into one nice machine.

First off, take a look at this nice backglass. I really lucked out when I bought the 2nd machine at Gary's. The backglass is almost perfect. Just click on the thumbnail below and take a look.

JP Backglass   JP Backglass

I finally started working on this machine around the end of July 2001. The playfield is in excellent shape, plus I have a spare for parts and to use as a reference. Here's a couple of "before" pictures I took. I've included one of the first machine I got too, just so you can see much better the one from Gary's is.

Picture #1
Picture #2

The first thing I did was to remove everything off the top of the playfield, including all the posts, plastics, side rails etc. I like to do this first off so I can clean it real good. Then I removed all the subassemblies from the underside, including all the drop targets (3 banks), the flippers (3), the sling-shot (1), the pop bumpers (2), the ball ejector, etc. Basically, everything but the switches and lamps came off. I did however remove any switch that poked up into the playfield. Leaving this on makes it hard to clean and wax the playfield.

The next step was to wipe the playfield down with a rag soaked in naptha. I did this to remove any old wax. Then I followed up with a good cleaning with Novus #2. I worked real hard to remove as much dirt and grime as I could. This playfield was in much better shape then my Power Play and it cleaned up real nice. There was only a couple of real small paint chips, and I mean real small.

I then replaced the loose mylar rings under the pop bumpers with stick-on rings. I don't like the loose ones and they just get messy and trap dirt, etc., so I got rid of them. I decided against mylar in front of the sling shot (Joker Poker only has 1 powered sling shot). I will watch this area closely and at the first sign of wear I'll put a mylar "D" in front of it. After I cleaned the entire surface and put mylar circles under the pop bumpers, I started to wax it with Johnson's Paste Wax. I ended up giving it 5 coats, which was enough! The last two coats took a lot of work to buff it off, so I stopped at 5.

I then replaced all the stuff underneath the playfield, but not before I disassembled each subassembly, cleaned it, checked it out, and put it back together. Most everything was in pretty good shape. There were several broken drop targets, but since I had an extra machine, I had enough. I had to re-ink a few with red and black Sharpie pens though. I also replaced the crappy lamp sockets in the two pop bumpers with wedge-style sockets. They are much better (in my opinion) than the ones originally there. Bally uses the same crappy style too and if these turn out as nice as I think they will, I'll replace the ones in my Power Play with wedge sockets too.

While I was installing all the stuff under the playfield, I had a lot of trouble re-soldering wires back on the coils. I noticed there was some kind of stuff on the wire as I stripped back the insulation, something greasy that would not let the solder stick to it. What a pain. Sometimes if I stripped back far enough I could find clean wire, but many times I could not. If I applied enough heat with my soldering iron, I could get some of them to take, but a few would not. On a couple of wires I had to get some crimp connectors and crimp on a fresh piece of wire. I figured a good tight mechanical connection would suffice, then I soldered the fresh wire where it needed to go. This problem was very strange. I posted it on, and a few others have had this problem too. Turns out that the insulation on the old wires (20+ years) leach some kind of substance and this stuff coats the stranded wires.

The next step was to replace everything on the top of the playfield, after each piece got a good cleaning. I even cleaned all the plastic posts with Novus #2 (actually, I had my daughter clean them). I buffed the little stainless steel acorn nuts too so they were nice and shiny. Any exposed metal, even screw heads, got a treatment on the buffer wheel. I replaced all the rubbers and lamps. All th main flipper bats were cracked to some degree, so I had to order new ones. The little flipper up top was fine.

Finally I reinstalled the side rails. These are plain pine wood with a woodgrain vinyl stick-on covering to make them look like maple. I almost decided to replace them with real maple but then I noticed there was a metal lane guide riveted to one of them and I figured I'm mess the guide up trying to remove the rivet, so I just cleaned up the vinyl covering instead. Then I cleaned up the apron and top arch. Both these pieces were in pretty good condition, as you can see in the "before" photos above, but with a gentle cleaning with some Novus #2 (gentle cuz it takes paint off if you rub too hard), they got even better. Now the playfield looks fantastic. Take a look for yourself, I'm really excited about how nice this playfield turned out.

Picture #1
Picture #2
Ball's Eye

Now that the playfield and cabinet are all fixed up, the next step is to put the head on. I also replaced the power cord with a nice new one, and replaced a couple of busted fuse holders on the bottom board. Once the head was mounted in place, I dug out the box of circuit boards so I could put them in place. I have two MPU boards so I'm pretty sure I'll have a good one to work with - wrong! I take a look at the first one and see there's quite a bit of acid damage from where the nicad battery used to be. The corrosion goes up into components and has completely etched away some of the traces, so it's trash. I whip out the other one and it looks pretty good, and the battery is already gone. I get ready to drill a hole so I can mount a memory backup capacitor and that's when I get a good look at it and notice there's some corrosion on this one too. Not much, but enough to eat away at some traces and mess up some of the edge connectors. Rather than try to fix it, I decided to trade them both in for credit against a new Ni-Wumpf from John's Jukes in Canada. John Robertson gave me credit for my two bad System-1 MPUs and quickly shipped my new Ni-Wumpf board to me. These boards are designed with all System-1 games in ROM, so all you have to do is set the dip switches to correspond to your game and you're all set. The settings are stored in EEPROM so there's no battery necessary either. I highly recommend one of these boards to anyone with a System-1 machine that is experiening any MPU problems at all. They cost under $200 and are well worth it. Nothing like eliminating your MPU from your list when you're troubleshooting a problem. Here's a nice photo of the Ni_Wumpf in place (click on the thumbnail below to see a big picture).

While installing the new MPU, I noticed several of the connector pins that connect to the lower portion of the MPU board were also corroded from earlier battery leaking. So I removed the bad ones and crimped on new connectors. System-1 boards use edge connectors instead of header pins. I also noticed two of the edge connector housings were in bad shape. Finding new housings is almost impossible, but since I had a spare playfield (again - a good thing to have), I was able to use a couple of them to replace the two bad ones I had found.

After replacing all the corroded connectors, I decided to test the power supply voltages before applying power to the new MPU, just to be sure. All checked out OK, so I hooked it up and powered the machine up for the first time! The chimes chimed, the displays displayed, and all seemed OK, but the ball did not eject, and the knocker is real weak (I love the loud knock so that has to be fixed). I manually ejected it and played my first ball. Very nice, and it brought back all my college day memories, but man does this pin ding a lot. There are a few things worth 500 points, and when the action gets hopping, the 100 chime goes nuts. Anyway, I play a couple of balls this way, then I break off a Jack drop target. I guess the one I put in when I overhauled them was cracked. It was my only red one. No big deal, I replaced it with a black one. I'll order another red one from PBR later.

To attempt fix the eject hole, I first checked it's fuse. This machines has lots of fuses under the playfield, one for the ball eject solenoid, and one for each drop target reset solenoid. The fuse was OK so I assumed there's a bad driver transistor, so I order spare parts for the driver board (all three types of transistors), plus some spare parts for other boards too. The parts arrive and I replace the driver transistor for the ball eject. Another test and it still does not work, plus I can hear the coil humming, so I shut the machine off. So I start looking at the Ni-Wumpf board and in the manual they mention some diagnostic information. I get my handy DMM and start checking parts. Turns out there's a bad hex inverter on the Ni-Wumpf that delivers signals to the driver board. This hex inverter is bad and constantly applies a signal to the driver board to energize the ball eject coil. I call Ni-Wumpf and ask them if I can fix it myself w/o voiding the warranty and they say "sure". Turns out the inverter is an older part that I can't find anywhere but Jameco, so I order a bunch so I have some spares. The parts come in, I replace the faulty one on the Ni-Wumpf, and use a socket this time, and that did the trick.

The machine now works just fine. The only thing wrong with it is a sluggish knocker. After a closer look, it turns out that the coil plunger was in upside down (nylon post down) so when energized, the plunger just stayed inside the coil. When I turned it right side up, so the nylon post was pointing up, it would properly strike the metal plate as it is supposed to, but man, what a whimpy knocker - not very loud at all. I took out the original knocker assembly, got an extra Bally assembly and swiched the coils, then mounted it on the floor of the cabinet so it strikes the side. I also put a small piece of 1/8" aluminum on the cabinet for the plunger to strike. It's still not as nice as the knocker on my Power Play, but lots better than it was. Click Here for a picture.

One thing about Joker Poker is that you go through the drop targets. I've broken about 6 of the targets that were originally on my machine. I finally broke down and bought a new set from PBR (at $4.00 per target). Click Here to see a picture w/ the new targets installed - real nice!

Towards the end of October 2002, I decided that since the playfield looks so nice, I thought it would be a good idea to have it clearcoated to protect it. I got in contact with Bill Davis and sent him the playfield. He's going to touch-up a few places then clearcoat it. Before I sent it to him I had to remove everything from the surface (again) plus I removed some of the heavier assemblies from underneath, to save on shipping. I got it back in January and it looks fantastic. I also bought a new set of reproduction plastics. These look exactly like the originals and will make a nice addition to the newly cleared playfield. With the cleared playfield, the new plastics, new drop targets, and new flipper bats, the playfield looks brand new. Click Here and go take a look for yourself.

Check out how I added Pop Bumper Driver Boards to my Joker Poker to liven up the pop bumpers.

If you're looking for parts for your Joker Poker, or other Gottlieb machine, you might find some here.
I also do Gottlieb board repair work. If you need some work done, look here

Here's some more information on Joker Poker, if you're interested. If you own a Joker Poker machine but do not have a manual for it, some of this stuff may be of use to you.

Rubber Ring
Rules of
Joker Poker
Dip Switch
Fuses Solenoid and
Lamp Info
Coin Door
Pop Bumper

Here are the Joker Poker Flyers if you want to take a look:

Thanks to An Ugly Flyer Reference Site for their nice collection of pinball flyers, including Joker Poker

If you own a Joker Poker, I'd love to hear from you and share info/parts/etc. Just send me an e-mail Mail Icon by removing the NO_S*P*A*M_ and tell me all about your machine.

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Created 2/28/01 - Last Modified 6/2/10 - Steve Kulpa Mail Icon Nolensville, TN
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