Dirty Harry
Williams, 1995Never ran into this before. Switch matrix test shows all switches in rows 1-7 as closed. Disconnect switch wires from CPU board and turn to open (except 24, which is NC).
I have a GLM 16-opto board installed, and it is showing weirdness also. Remove the connection to the CPU board and the issue clears also (same as unplugging CPU board).
Getting 15VDC from the power driver board TP1 (powers the optos, motors, etc.), which is higher than the 12V nominal value.
Any ideas?
The top L connector maybe be off by one, however I took the picture after throwing the board back in temporarily. It was working fine and then the problem arose when the board was installed for a while, so I suspect the issue is not related to an misconnected connector.
Anyone had this switch issue before?
Anyone had issues from an excessive 12VUR line?
If the problem goes away when you disconnect the GLM board then I would suspect it.
The 12 volt unregulated will run high. I typically see around 14 volts, but don't think 15 is out of the question.
Whether it was the original problem or not I would still check the plug. It doesn't look a pin off it looks like it has been rotated 180 degrees (again, just based on the size of the gap).
Quoted from terryb:It doesn't look a pin off it looks like it has been rotated 180 degrees (again, just based on the size of the gap).
It kind of does, but the wires in the bundle are running off in the correct direction.
I can see that someone was trying to directly solder wires to the pins on the lower right connector. Tisk, Tisk.
So you are saying that removing the .156 header, top, center of the board causes the issue to go away?
Do other switches work correctly when you remove that connector?
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info
A couple of things:
We sell the 16 opto board physically configured for ST:TNG (meaning the CPU connector is mounted towards the playfield). Most other games orient the board so that the connector is pointed away from the playfield. Also, some games don't use the brackets but mount the board horizontally against the playfield using plastic standoffs. I don't remember which way DH is configured.
The way the 16 opto board connects with the switch matrix is through floating transistor buffers, meaning there is no direct path to ground between the row/column lines on the board itself. The board relies solely on the CPU board providing the proper drive signals. As such, there isn't really any way for the 16 opto board to completely short out an entire switch matrix on it's own.
It would have to have some form of outside help.
My first instinct would be to replace the ULN2803, the chip that drives the column lines. If one of these has shorted out or is stuck "ON", it could basically cause the row lines to be active across all columns instead of just the one column. Since the 16 opto board sits across two columns, there is double the chance that a bad column driver could cause the board to affect the switch matrix in that way.
Hope that helps.
Thanks for the input everyone, will check the CPU board and use an OEM opto board for troubleshooting.
Did a bench test of the opto board and it seemed to be behaving very oddly. I applied power (12V) to the board and started connecting a couple test optos and the two red bar LEDs started giving really weird readings. I should have shot a video for posting, but did not.
I will report back when I have more info.
Quoted from adalogue:It was working fine and then the problem arose when the board was installed for a while
Do you have the original 16 opto board to put back in the game?
Quoted from ChrisHibler:Do other switches work correctly when you remove that connector?
I hadn't seen an answer for Chris' question.
Yes, other switches work when removing the switch matrix connector on the opto board.
Yes, I have an OEM opto board I will try and report back.
Quoted from adalogue:Yes, I have an OEM opto board I will try and report back.
Good idea!
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info
Quoted from adalogue:Yes, I have an OEM opto board I will try and report back.
Yeah, I was wondering if the machine can with the GPL board or not.
What was the reason for wanting to upgrade?
The board can't be tested the way you are doing it in the video. You need to power the IR LED from the appropriate header since each one is pulsed and timed to correspond to the matching receiver. By doing it the way you are (powering the LED continuously) you are flooding the input channel which is duplexed, which is why two red LEDs are lighting up at a time.
Also, by not having the IR LED plugged into the appropriate connector, the board thinks that there aren't any attached or that there is a short in the wiring harness (the reason for the two rapidly blinking red LEDs). When this occurs, the board goes into a special fail-safe routine designed to test each of the IR LED lines and prevent damage to the on board transistors.
In short, it may be harder for you to test the board outside of the game without a special testing rig.
Also, I would be guessing that you don't have a manual for the board, which would give you a lot of information on what the board is doing and why. If you would like a copy, just send me a PM or email at: [email protected]
Ended up being a switch matrix issue, as GLM suspected in posts above. I had recently installed new U20 and U23, so had been diverted from checking them, but both were bad. Not sure why those chips aren't lasting. 
Thanks to my trusty Siegecraft switch matrix tester, it showed three bad columns. Two were fixed by replacing U23 and the other by replacing U20.
Thanks everyone!
Update: threw in working CPU board and GLM board not working right. Swapped out with OEM opto-16 board and everything is dandy. Will check with GLM to see what sort of service they offer on their boards.
Quoted from adalogue:Swapped out with OEM opto-16 board and everything is dandy
Any particular reason you installed the GLM in the first place? Was it because you thought the original opto-16 board had an issue?
Quoted from PinballManiac40:Any particular reason you installed the GLM in the first place? Was it because you thought the original opto-16 board had an issue?
I thought it would be handy to have the emitter and photo transitor LED status lights that are on the GLM board for troubleshooting, quicker to know if an opto transmitter or receiver is the culprit, etc.
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Banning, CA