Doctor Who
Bally, 1992You're currently viewing posts by Pinsider topkat.
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When I boot the game the opto popper , switch 31, continues to fire. Test report says check opto popper
I replaced both optos and it still doesn’t register in test.
I checked/ reseated j6 on the opto board and no change
All the other switches test correctly
How do i rule out opto board vs cpu
Quoted from LTG:This might help - https://www.pinwiki.com/wiki/index.php/Williams_WPC#Opto_Switches
LTG : )
Thanks.
Is there a similar way to test the 10 opt board?
Pinwiki has a good write up on the board itself, but not a way, that I see, to test the board?
Quoted from DumbAss:The CPU board only sees rows and columns. It does not see individual switches. If this switch is the only misbehaving switch then it's not likely to be the CPU board. You can rule it out using the procedure documented in the Pinwiki.
To differentiate between the opto pair and the state detection on the opto board follow the procedure documented in the Pinwiki (linked above) under the topic "Test the LM339 comparators". If you have replaced the opto pair AND the CPU board sees all the other switches in the same row (1) and column (3) then it's most likely to be isolated to the opto board.
These things come to mind:It is possible that if the opto board connector (J3) is the last connection in the daisy chain (parallel wiring) and the wires are loose (not making proper contact) or disconnected. It could also be the connection at the previous point in the daisy chain has come loose.
It is possible that you have wired the receiver (CE) incorrectly or the phototransistor installed on that board is "reversed" (i.e. C leg installed in E hole and visa versa).
It is possible the LM339 unit responsible for the state detection is damaged and not working correctly.There could be other things as well.
Thanks.. To be sure I am providing the correct info. That opto switch always registers open. Thats why I assumed at first it was a bad opto, but even after replacing them I cant get the opto to register closed.
I will check all the items listed above..
Quoted from DumbAss:I hope that's not the board you received because it looks like the key pins have not been cut. That board is also the vertical mount version (wider) and not the (original narrower) horizontal mount version.
The 10-opto board services 7x switches in column 7 and 3x switches in column 3. You can apply the procedure for the 7-opto board in the Pinwiki for the 7x switches in column 7. For the 3x switches in column 3 you will need to apply the electrical procedure for J4/J5/J6. These individual connectors contain the AK/CE pairs for each individual opto pair. J6 specifically corresponds to switch 31 (according to the manual).
Thank you..
Thats not my board, I just grabbed a photo since I was at work and wanted to know what the difference would be
Quoted from Tophervette:I have had several issues in the past with Switch 31 Opto popper, so these are my uneducated ramblings. First I had a wire that goes to the Tardis light that would block the Opto when the playfield was down but not when it was propped up. A ty-wrap fixed that. Second, the plastic cup that pushes the ball up was old cracked plastic and got caught returning, also blocking Opto. Replaced it with new part. If lived closer, I could loan you my DumbAss Opto tester that I built from his kit. As a shameless plug, I am including a picture of the 10 Opto board, that I just built from him as well. J6 runs directly from the 10 Opto board to the Opto Popper with 4 wires. I replaced the IDC's with a molex 5 pin plugs. I also included a picture of the Opto popper that I rebuilt.
[quoted image][quoted image][quoted image]
I pulled the bracket that has the optos when I replaced them. Even with the new optos there is no registration when I try to activate it. Its as though the switch doesnt exist. Dumbass gave me a good list of things to run through, and I will try those next. But I guess if I had the opto tester Id know if the optos were working and if the opto board was sensing it. If I come up empty I will have to get one. Thanks
Ok I removed j206 and j208. I used a jumper and all the switches show up when activated.
I believe this rules out the mpu..?
Quoted from eyeamred2u:Kinda looks like corrosion from acid damage off if the MPU.
That connector definitely needs replacement, but the rest of the switch register in that row. I had a terrible time repinning the .1 pins. I got them crimped but couldn’t get a good fit in the housing. I’ve done a number of the .156 and they turned out well.
I think I am going to with a new idc instead because some of my pins are suspect.
Hopefully this will help someone else in the future.
It turned out the new opto set I installed were faulty. That led me on a goose chase assuming it was something more involved. So Always make sure the new optos you install are functional.
Thanks to @dumbass’s new opto board I was able to determine the problem was from my optos and nothing more.
Appreciate all those who chimed in. Next up to try and get the demogorgan in position to swallow the ball!
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Gresham, OR