Just purchased this as a rescue project. I have a new score reel coil and wiring diagram on order from the Pinball Resource and look to receive this by Monday of next week.

Two of what I know as the biggest problems are:
1) The 100 Point bell coil latches on when the points are first made (with out the drawing I'm struggling a bit here. Any help or diagram shots would be
appreciated). I isolated the contacts with the White W/Greene & White W/Red when the coil is energized and this unlatches the coil (See photo).
2) The Silver Bonus Stepper Unit doesn't move correctly at all. The teeth are worn and the shaft drags even after disassembly, cleaning and applying
lithium grease to the shaft. I have a spare Williams Credit Stepper but the gear is cut differently. I may just try swopping the bearing out to see if this helps.

Side Bar: I have a need for a back glass for this title. It came with a "Joker Poker" back glass. Happy to trade this back glass for a Prospector or by your Prospector back glass outright.

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Thank for the tip. All four score reel's EOS are made and open when actuated. Must be elsewhere in the circuit. - Tom

Sounds great. Every one of mine is either chipped or cracked.

I just got a notice from the post office my shipment of the schematic and parts from PBR is delayed with no estimate of an arrival date presently after 6 days of waiting. I had hoped to find a schematic here to tide me over or on the web for this game but nothing. Its frustrating.

I have having trouble sorting this one out. The Silver Bonus unit is worn out. I have disassembled and cleaned all the old grease and re-lubed it and the contact paths. The teeth are so warn it doesn't step the proper distance and it will slip and then the contacts don't make as they are supposed to. This causes all kinds of issues. The sliver one has similar issues but just not as bad.

I have found that sometimes folks here are not so willing to share wiring diagram information. A common complaint with EM's is the score motor keeps running. I thought I would share this here for the groups benefit.

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Well I have cleaned rebuilt the silver bonus with new springs and used Super Lube to thinly coat the contact path. Now it will operate consistently.

After powering up all seems well. After pressing the start/credit button everything appears to reset well but at the conclusion of the cycle the Silver Bonus Advance RE is held on. Also the 100 P RE coil is also held on. I will begin to go through these circuits to see if I can discover the reasons I am having this trouble. My first thought is the Silver Bonus Advancetre NO. contact. Will see.

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While having a look around I discovered that intermittently The Gold Bonus Advance RE is held on and also the 1000 P RE coil is also held on. Yikes! It will occur when I jostle the play field by using the flippers. While having a look around I discovered that intermittently The Gold Bonus Advance RE is held on and also the 1000 P RE coil is also held on. Yikes! It occurs when I jostle the play field by using the flippers. While preparing to post this update I found the issue. The wire connections to the right Gold Bonus roll over contacts where to close to each other. - Solved

Back to the Silver Bonus Issues.

Hi guys, well EM pinball always opens up opportunities to learn. In order to reach the bottom of the playfield I pulled up and then back to reach it to make the repairs to the silver and gold bonus units. I had to move the machine and set the playfield down. Later I powered it up to check it out and for three balls it played perfectly. The reason for this is gravity effects the proper operation via the spinning targets which will cause various coils to stay on and even burn if your not on top of it. I used painters tap to hold them in place.

The next problem was when the the ball would enter the L. Eject Hole or the Center Eject Hole the it would score 5000 Points over and over and over. the ball would not kick and if you removed it yourself there was no change in its status. You can imagine every I needed to check and there was no change to this. The condition of every contact on the drawing was open preventing this from happening. I examined every wire connection looking to find a fray or bent over connector, something to supply a ground. I did notice a slight blue flash coming from the Silver Bonus near the Zero Position Switches. They were all like I said as they should be. I recleaned and gaped them them again. I wiggled the Zero Position Switches assembly while the it was stuck in the scoring loop and once in a while I could get it to stop. As it turned out the Silver Bonus Unit, Open at Zero POS. SW. contactor was touching the uninsulated tip of the Ratchet pin creating a new circuit to ground. I do still have a few strands of hair left. I'm off to see what else is left to figure out.

No bells on the slingshots and the NO.

Match Unit needs to re rebuilt. I could use a good set of photos of the NO. Match Unit contact/actuator. This is the type it has. I need to understand how the contact is to be shaped (circled).

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I believe I have the NO. Match Unit contact bent correctly. I need to install it now. I have not been able to find these contacts in the wiring diagram. Anyone? I will need to comb through it again.*

I have the slingshot bells operating now. It was a pair of contacts with the paper between that has a passthrough hole for the contacts to meet. the paper was curled on both slingshots preventing contact.

As far as I can tell the last electrical item with this will be one or both of the alternator coils are not coming on.

*Note: While reading the instruction manual I found that both Alt. 1 & Alt 2 are energized by the NO contact on No. Match Unit.

Well I have a new problem that is troubling my Prospector. When play a single player game ball 1 and ball 2 score on the 1st player reel. Ball three scores on the second player reel, ball 4 on the 3 player reel and ball 5 on the 4 player reel. I guess I will start with the player unit and figure out how it advances the players. Something is telling it to advance on ball counts 3,4,5, is the ball count unit involved? Anyway, the schematic should reveal something. Your suggestions or guidance is always appreciated.

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It seems my problem above isn't as straightforward as I thought. I wasn't able to adjust my problem away regarding the player reset contactor. So I wanted to see if there was some sort of a timing issue so I wired up three 24 v bulbs so I could see how the circuit fired. I wired one bulb to the Player Reset Contactor Coil (R-G). This signal originates from the Ball Count Unit EOS switch. There is a M&B on the Player Reset Contactor. I put the second Bulb on the N.O. that pulses to the Player Unit Reset Coil (G-Y). The third I put on the center conductor of the M&B (The print says W-BR but its a typo. Its W-R). I did all of this so I could see if the timing supported the circuit's completion. I have a video of it working and failing but I can't load the videos in this post. It works when the player reset coil stays on longer. It fails when the player reset coil is on for a split second and it’s a fails to hold long enough for the center conductor of the M&B to get the signal to the N.O. Contactor going to the Player Unit Reset Coil.

Bottom line is I need the Player Reset Contactor Coil to hold longer like it does when it works. How do I get it to stay energized longer?

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I had gone trough the entire Score Motor about six weeks ago when I had the entire control board out of the machine and on a table. The gap on the Index cam Level B on the M&B contactor R-Y wire was acceptable but could be dialed in a bit closer. I swear these Williams contact arms are so robust they have spring memory. I closed the gap for optimum performance (again). This has fixed the problem. I needed to be convinced to go back and have a second look apparently. Gap seems to be totally dependent on what the design of the circuit is, not a predetermined gap distance (which does work much of the time). Thanks for your valued direction.

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