When I first power up my TAF, it gives me this test report: Check switch 31 upper left jet, check switch 41 grave "G", check switch 51 shooter lane, check thing eject hole kick out. I have examined the wiring that goes to each switch. It seems to be connected and the diodes are going in the correct direction. When I run the switch test, I can manually press these switches with no indication or response on the display. Can I remove the J206 connector and the J208 connector and manually jump a wire between the intersecting pins to see if I get a response on the display? Will it cause any damage if I just jump the pins on the CPU board? If I get a response there, then I guess I need to keep looking for an issue somewhere on the playfied with wiring, connectors or switches? Any help would be greatly appreciated.

Thanks for the responses. As far as I can tell the only two switches working in that row is 61(left Ramp enter) and 81( Book Case open). I have searched for any wire that may be common to all the affected switches. I thought there might be a wire broken or shorted at 61, but I can't see any.

Thanks for the response. I've look and looked for broken wires and loose connections underneath the playfield. I've resoldered some connections and even replaced a couple of switches. Still no results. I'm starting to think it's something in the head or back box. I'm going to closely inspect the connectors and connections on the mpu board. It's even been mentioned that a chip could be out causing a whole row of switches to not work. I have learned a lot about troubleshooting and the switch matrix. Still looking. Hopefully everyone will keep suggesting until I find it. I think it's going to be one single cause for all the affected switches.

Thanks for the advice. I will check the continuity between the switches and double check the diodes.

I am finally making some progress. I am finally getting a response from the "G" target 41 , Shooter lane 51 and the upper swamp lock switch. After weeks of looking, replacing switches and testing I found that inside one of the connectors, two wires that were crimped together weren't making good contact. After replacing and crimping the bad contacts inside the connector, I'm getting a signal to the switches on that row. Hallelujah! I was able to check this by using my meter to follow the continuity starting at the back box and going from switch to switch. The current was flowing into the connector but not flowing out the connector to the next switch.
I am still getting the error message about "check the thing eject hole", but one step at a time.
Thanks everyone! Any help with thing eject message will be appreciated.

Thanks for the advice. I am a beginner in learning to troubleshoot, but I gained a lot of experience and knowledge in the last couple of months by reading Pinside, studying the manual, Pinball Rehab and other online resources.
I still have one upper left jet switch(switch 31) that I can't get to work. I know I'm getting continuity from the row side wire, but maybe the column side, green wire is not getting a signal from the next switch in the daisy chain? The solenoid test works on that bumper, but I'm getting no response from the switch.

wellarmed: I will try throwing a ball in there. Hopefully that is all it needs. It seems to work just fine, but I keep getting that report. Thanks!

I will try cleaning the contacts first. Then I guess I'll start tracing the continuity on the green/gray column wire from the back box through each wire, connector, and switch. Thanks!

I tried shorting the white/brown and green/orange wire at the switch. I had no response. I tried cleaning the contacts and verified I had continuity from the back box to the switch. I have replaced the diode and resoldered the connections on the switch. I'm not sure what to try next. The solenoid test shows the solenoid to be working. Any help would be appreciated.

Thanks for the response. So far, I have been unable to find a bad connection going to that switch. I used my DMM and verified I had continuity to the switch. I'll keep looking. Thanks!

wellarmed, I appreciate your help. You won't get on my nerves . I was able to find a bad crimp connection in one of the connectors that fixed most of my switch issues. I followed it down from the cpu board. Question: Why are you saying to pull all the switch connectors at the cpu? Is it because you get a false reading or something if it's plugged in?
I just posted another question in the forum about the ball or more than one balls getting lost in the swamp. If you have any thought on that, please let me know. Thanks!

Thanks! I will check it out and let you know what I find.

I am still trying to figure out why switch 31 at Upper Left Jet is not working. I used my meter and verified continuity from the connector in the back box all the way through each switch. I verified continuity of the white/brown wire and the green/orange all the way and it's connected. I'm pretty sure there are no broken wires along the way. I did see underneath the playfield that there were some grounding straps from the pop bumpers were broken. I resoldered them back in place. I am getting no response in the edge test. I even tried to short the switch directly with no response.
Should I be checking voltage at the switch?
Should I disassemble the pop bumper itself and look for cracks? (It's in a difficult place to get to.)

Any help would be appreciated. Running out of ideas. Thanks!

I was just looking at the switch matrix. Should it be j206/3 and 208/1? Do I have to remove the connectors from the boards and pull the wires from the connectors leaving only the oranges? I would prefer leaving them connected in their connectors since I'm not sure I can get the wires back in the connectors. I would prefer to leave the connectors and wires on the mpu board and just short j206/3 and 208/1 with a jumper wire. Will I cause any damage if I do this?

OK, Thanks! I will try that when I get home from work.

wellarmed: I disconnected the connectors and bridged the pins, I get no response from switch #31. Not sure what this means. Could that mean that a chip on the board is bad or the whole board is bad?

I jumpered the pins and got no response from #31. I will try more tests tonight. It seems the other switches are responding. I disconnected the board and removed it from the back box for a close visual inspection. I couldn't see any battery damage or any kind of hacks or bad looking solder connections. The board looked pretty good. It seems only that one pin is bad.
I am thinking about buying a replacement board from Rotten Dog. (or should I try something else first?)
Maybe I should replace U-18? or another chip? My question is where do I find a U-18? Is it known by a longer part number or something? Thanks!

terryb: I will jumper the pins one pin at at time and report back. I will check it when I get home from work. Thanks!

wellarmed: Thanks for letting me know about the name of the chip (LM339). I probably won't try to solder on the board myself. I would probably make it worse. I've been glad to find out that replacement boards are available (if all else fails). I found out the other common chip is a ULN-2803A. Finding out more every day. Thanks!

terryb: When I jumper the following:

J206/3 to J208/1.... no response
" to J208/2.....upper right pop bumper
" to J208/3.....left center pop bumper
" to J208/4.....right center pop bumper
" to J208/5......lower left pop bumper
" not used
" to J208/7...........left sling shot
" to J208/8...........right sling shot
" to J208/9..........upper left loop

J208/1 to J206/1.............no response
" to J206/2 ...........slam tilt
" to J206/3............no response
" to J206/4...........grave "G"
" to J206/5...........shooter lane
" to J206/6...........left ramp enter
" to J206/7..........swamp lock upper
" not used
" to J206/9..........book case open

I guess I understood your directions? From J206/3 to all pins in the rows and from J208/1 to all pins in the columns?
I can start by replacing U18. I could even get a scope if it would help. I'm not against replacing the whole board. I guess one from like Rotten dog?
It seems that most everything is working except the #31 Upper left bumper. I appreciate your help with this. Please advise. Thanks!

When you said J203 pins did you mean J206?

Thanks for your help! I went to an electronics shop today and found a LM339 chip for U-18. I thought I would replace that chip just as a precaution. To eliminate that possibility. After inspecting again I discovered it is soldered in. I also discovered someone had replaced ULN2803 chip in U-20. I just don't feel confident soldering on the board. I'm afraid I'll just make it worse.
I removed the board so I could inspect the board more carefully for visual damage or hacks. I looked carefully on the front and back for anything obvious. Maybe I don't have the experience to know what I'm looking for.
I'm not against trying the rottendog board. I've seen people post issues with reset problems with some machines but that could also be related to something else. Seems like TZ is mentioned more often with possible issues. I don't mind buying a scope, but I'm not sure I could repair the board anyway.

Can you recommend someone to repair my board? Or, if you do these type of repairs/soldering, I would be glad to pay you. I didn't see any obvious battery damage, but it is probably hard to spot. I will try to snap a picture and post it. Thanks!

TAF CPU board

TAF CPU board 001.JPG

TAF CPU board 002.JPG

I went ahead and ordered a Rottendog replacement board. Rottendog MPU for WPC 89 Plug and Play, MPU089 Replaces WPC A-12742. It will also be good to get to the batteries off the board. In the meantime, I will be looking to find somebody or a company to check out or repair my original board.
terryb: Thanks for all your help and suggestions. I may reach out to the names you mentioned for board repair. It's been a great learning experience and it's been fun getting back in to the pinball hobby. I don't think I would have gotten this far without the help and support of Pinside and it's members. I'll keep you posted. Thanks!

I received and installed the Rottendog MPU board. It seemed to resolved almost all of my switch error messages including switch 31 upper left jet, switch 41 grave "G", switch 51 shooter lane, check thing eject hole kick out. Each one of these switches are working now. Glad to get this much working.

I'm still having a couple of weird issues I would like to get some advice on:
1. When I get all the GREED lights and the book case opens, The Thing/hand will immediately come out. It will cycle a couple of times, then stop.
2. The upper left jet bumper is working now, finally, but when the upper left bumper kicks, it also fires the left sling shot and the right sling shot. Weird. I don't think it's because the contacts on the slingshots are adjusted too tight and just vibrating from the kick of the bumper.

Any help would be much appreciated. Thanks!

Miguel351: I will keep looking for broken wires, bad diodes etc. I have looked and looked but haven't found anything yet. I will keep looking. I am getting a better understanding on how to systematically trace the wires and the switches through the switch matrix.

terryb: I will go into switch edge test and run the tests you are suggesting.

Thanks for the advice and I will report back, Thanks!

terryb: I went into the switch test and manually closed the upper left jet bumper. The slingshot switch didn't show as closed. It seems that when the bumper switch also triggers the sling shots, it only during game play. It seems the book case switches are operating correctly. When running the book case test, it seems they are opening and closing correctly.

I am still tracing wiring and switches and cannot find anything unusual. I have inspected for any bad connections or anything obvious. I never get the easy ones . I will keep looking. I would really like to get this machine working correctly. I will keep looking. Thank you terry and miguel for your suggestions.

Thanks Terryb, I will check it again for vibration problems in the jet bumpers. I actually removed the bookcase last night and was able to drop it down below the playfield and hold it in my hand to be able observe the opening and closing of the bookcase switches. It seems the switches are opening and closing correctly. I may leave the bookcase unplugged and operate the game with the bookcase open and bookcase closed switches unplugged from their molex's. Just to see what affect that has. I'm still hoping to find a wire crossed, a direct wire short or a bad diode somewhere. You would think something like that would be easy to find, but it hasn't been. I'm back to tracing wires and wiggling diodes. I guess you have to disconnect one leg of the diode to be able to test it? I'm pretty certain that the bands on the diodes are facing the correct directions. Any other thoughts would be greatly appreciated. Thanks!

I tried pounding on the playfield to see if any of the pop bumpers fire. No Response. It seems the slingshots fire only when I manually activate the upper left jet bumper. When I activate the other bumpers there is no response from the slingshots. It only fires the left and right slingshots during game play. I think I will replace the switch and diode on the upper left jet bumper and see what happens.

I don't know if this has anything to do with the issue of when the upper left jet bumper fires it will also fire the two slingshots. After inspecting around the pop bumpers, I have found the metal strips that connect the lamp circuits is all hacked up. I can't tell if the metal strips are suppose to be grounded to the pop bumper screws or if maybe this is part of my problem. It just looks like something is not right. It looks like the plastic tubing is out of place that would insulate the metal strip wires from touching the metal parts of the pop bumper. I'm asking for someone to look at these pictures or I would really appreciate it if someone would snap some pictures of this area so I could compare and put it back the way it is suppose to be. Thanks!lamp circuit2 001.JPGlamp circuit2 002-829.JPG

Terryb, that's kinda what I was thinking. If you could post a picture , I would really appreciate it. That hack job on the lamp wiring has been typical on how this machine was worked on before. It has been one step at a time to get this pin back in top shape. By the way terryb, I was able to rebuild the wiring and coin slot lamps after the pictures you sent me. Thank you! Please post pictures! Thanks everyone for their help!

LTG: Thanks for the response.

Wow, Thank you Terry! I will start on it tonight.

I finally got the switch issues resolved. When I would activate the upper left bumper if would also fire the 2 slingshots. It would only do this with the balls in the playfield. After further testing, I discovered that any switch in row 1, would activate 3 other switchs in that column. Very frustrating. I’ve been searching for crossed wires, shorted diodes, or bad connections for months. I started talking to terryb. He has been very patient and very helpful with me to troubleshoot this issue. From the very beginning he was saying that all the testing was pointing back to switch #11, but switch 11 is not used. What’s weird it was showing switch #11 be closed in the switch matrix. Terryb is a professional in the electrical and electronics field. He was able to go back to the schematics and see that switch #11 is used on the driver board. He determined I was getting the issues from the U8 chip on the driver board which was shorted and causing the #11 switch to show to be closed. My soldering skills are not up to working on a board so I went ahead and ordered a Rottendog driver board and installed it. After installing it and powering it up, everything is working correctly now. There were other issues along the way, but the new board completed the issues. It has been an invaluable learning experience. Thanks to everyone who participated in this forum, but I really appreciate the help from terryb.