After about 5 years of being in storage, I finally decided to dust off my Jurassic Park Pinball Machine and get it going! I knew there were problems with it when I bought it, but the playfield is in perfect shape and I couldn't resist. Here's what is going on and what I did so far:
Power Supply Board Overhaul:
I first powered up the machine. Most of the lights came on and there were a few red dots on the DMD. No sound, no power to any coils, no display. The LEDs on the CPU were all off.
I pulled the power supply board out and checked EVERY component on it. Two of the fuses were burnt out (I replaced all of them with the correct value based on the JP manual). Also, I checked all of the capacitors with and ESR meter. I replaced C4, and 18000uF 25V capacitor with a 25000uF 35V cap. This cap looked fine when it was on the board, but after I pulled it, I could see it leaked out on the bottom. I also added a wire trace to the leg of a diode the cap traced to. That was all that appeared to be the problems with this board! I checked all the diodes, fuses, resistors and transistors too. I put the board back in, powered up the machine and the machine immediately went into diagnostic mode, the DMD worked fine and the sound came on when I started up the game. Also, the first two LEDs came on the CPU board.
Playing the Game
I started up a game. When I pressed the start button, a ball was placed in the shooter lane, but after pressing the shooter trigger the shooter solenoid did not shoot a ball onto the playfield. Also, both of the flippers were not working. It seemed also that not all of the lights were working, nor the flashers.
Flipper Board Under the Playfield
I pulled the flipper board from under the playfield. Sure enough, two of the fuses were blown (both 9V hold for each flipper) F2 and F4, both 3A slo blow fuses. I checked every component on this board too, and everything checked out ok.
I checked all of the fuses first with my ohm meter. F5 was blown, as well as one of the GI fuses and F6. I then checked the bridge rectifier out and the readings were fine for that. I check all of the transistors next. Q1 and Q2 tested with under .2 volts and Q3, Q4 and Q5 were all completely shorted! Why would these short out? That's as far as I got last night. I did not get a chance to pull this board yet and check all of the components. Anybody got any ideas????
While checking the fuses in the back box, I also tested the two 8A 250volt fuses above the big blue capacitor in the lower left side of the back box. The fuse closest to the capacitor was blown. Not sure what these are for. GI? Flashers? Must be flashers.... I did not get a chance to look it up yet.
My overall impression of Data East electronics is the boards were very cheaply made! I could tell that they were repaired before. There are multiple burn marks on the molex connectors and a lot of rewiring. The traces on the underside of the board are all bubbling up. No wonder there is a market for after-market PCBs for these boards!
However, they are so very easy to fix....
Please let me know if you have any insight on this game or if there is anything I should look out for. I will be pulling the PPB board this evening or tomorrow to check it out.