Those jumpers look crude, but if they were working before they should be working now. Ck your 12vdc going to the opto board. I had a BSD recently with all sorts of opto issues and the 12vdc was measuring 9.5. Turned out to be a bad bridge rectifier and capacitor.

That is a hack/repair, not normal.

Really tough to troubleshoot long distance! When you were messing with the connectors in the backbox, did you perhaps re-seat any of the ribbon cables? They do go bad and complete sets are available from places like Great Plains Electronics. Another thing to test is the 12v filter capacitor. Ck the same 12volts you did before, but put the meter on AC voltage. Anything more than .2 to .3 volts of AC there and the cap is going bad.

I'm very familiar with the TZ 10-opto board because mine drove me insane with intermittent problems for a long long time. You're problems are exactly like mine, and I'm happy to say that I fixed it!

My problem was ultimately that the 100 uF capacitor C1 on the opto board leaked, caused some corrosion, and damaged some traces. I think damaged traces were more of a problem than the capacitor itself, but I replaced the cap, added some jumpers, and I was back in business.

You should pull the opto board and look at it very closely. If the capacitor is bulging or if there is ANY sign of leakage around the capacitor (especially the leads and their traces), you should replace C1. Radioshack sells 100 uF capacitors.

Here are two Pinside posts I made about my problems. I pretty thoroughly documented my problems and solution. Good luck!

https://pinside.com/pinball/forum/topic/all-twilight-zone-optos-go-out-intermittently

https://pinside.com/pinball/forum/topic/opto-questions-twilight-zone-opto-board

I just watched your video and discovered that your problem is slightly different than mine in that only the five optos on column 8 are flickering on and off for you, whereas it was all 10 for me.

I still think your problem is the 10-opto board, mostly because you can see from the photo that it's trashed. I suspect you've got broken traces somewhere, which would best be discovered with a multimeter. Unfortunately, the fact that your problem is intermittent is going to make it a hundred times more difficult to diagnose.

At the very least, you should rest easy knowing that your worst case scenario is buying a new 10-opto board from Great Lakes Modular. http://www.greatlakesmodular.com/products/pinball/osb10b.html

It could certainly be the 10 opto board. But, if you are correct that you are reading 31.5 vac on a 12vdc line, that is an obvious problem.

Mayfair is there and they have alot of boards of everything Williams so they may have it

chip at u2 don't look to good,cracked joint left leg of r4. get the board mot linked for you. g.l. joe

I just seen that a corner is broken off of the plastic and it looks like something is on the top of the chip.(glue or ? ) joe

good find.but I would still buy a new one. joe

Sound like the opto in the ball lock is triggering. If the game sees a ball in the lock during attract mode it is going to kick it out so that it goes back down to the main trough for the next player.

Sounds like you have a switch matrix issue, maybe this helps, http://pinballrehab.com/1-articles/solid-state-repair/repair-guides/146-switch-matrix-theory-and-troubleshooting

Stop looking at the other stuff and figure this out. There should be NO ac voltage on the 12 volts! Swap out the driver board with a working one and see if the problem goes away.

Let's start by making sure you don't have a meter or technique issue (although the readings below are possible, they are pretty unlikely). Get a 9 volt battery and check across it in DC and then AC with your meter and see what the readings are.

Also what brand/type of meter are you using?

OK, so 88 is a switch, not an opto. My mistake. You do have a switch matrix issue. Possible root causes are a failed diode, a diode on backwards, switch wires soldered to the wrong lugs on the switch, etc. And also do what TerryB suggested. It does seem unlikely that you would have that huge amount of AC ripple on a DC line.

http://www.greatlakesmodular.com/index.html?http://www.greatlakesmodular.com/products/pinball/stnmcb.html

Click on products and find TZ opto board

You are correct. At least i'ts working on DC, so we'll go from there.

Firstly your opto board is shot. Even if it is working now it won't be for long. So order a new board and remove it from the circuit for the following tests.

With the board removed test switch 88 and see what happens.

Does switch 88 still trigger the whole column?

Also provide a photo of the opto board with the connectors installed. I'm not sure on TZ if removing the connectors breaks the column/row circuits (normally it doesn't, but you never know).

It doesn't. Disconnecting the opto boards leaves the row/column circuits complete - other switches will still work fine.

Thanks Coyote. That's what I figured, but didn't want to assume anything.

Sounds like two issues then. As I said before the opto board is fried, plus you've got a switch that isn't working, broken wire, etc. on switch 88. Replace the opto board and then go from there.

I'd add -
With the opto board disconnected, do ANY switches on Column 8 work?

You could be right - I may be thinking of Row 7 (something I had an issue with a few weeks ago.)

You've broken a wire or pulled one out of the connector. Check the CPU connector and the opto connector. Tug lightly on the wires and see if they easily pull loose.

Page 3-29 of the Twilight Zone manual shows connections on the CPU board. J206 and J208 are the connectors for the columns and rows of the playfield switches.

Page 3-16 shows how the opto board connects to the CPU board. The relevant pins on the CPU board are:

• J206-9, green-gray, switch column 8
• J206-7, green-viot, switch column 7
• J208-X, white-XXX, switch rows 1-7

If you disconnect J206 and J208, you can use a wire in switch test mode to connects rows to columns and determine if the problem is on or off of the CPU board. http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Switch_Matrix_Problems

If there is a problem on the CPU board, it coiuld be caused by battery corrosion. is there any correction under the batteries?

I just re-read through this whole thread to see if I missed anything.

The green-gray wire for switch column 8 seems to be causing you problems, but because that column is almost entirely optos, the wiring should be really simple.

• one end is at J206-9 on the CPU board
• it passes through J5-3 on the opto board (the connector has wires coming in and out)
• the other end is at switch 88, lower lock

I could be wrong about that, but I can't see why the wire would run anywhere beyond those three places.

In either case, you should be able to test for continuity between those three places, or particularly between switch 88 and the CPU board. I have a feeling that it's not going to buzz, meaning your problem is in the playfield and not the board, but I'm not sure why...

Did you see my opto thread on my Roadshow the other day? All my optos in switch test mode were flashing on-off-on-off-on-off. Is this what you're seeing as well? If so, pretty sure I know what is wrong.

Dan

Edit: Okay, I just saw your video. You have the issue I was having. Cold solder joint on one of the legs of the big capacitor C30. Could also be a cold solder on the BR in that area or the connector right there. This is causing you to not always get the voltage you need at the optos themselves, which causes them to flicker on-off-on-off back to the switch matrix. Luckily this area of the driver board is a very simple circuit. A cap, a bridge, a connector, and TP1.

Here is my thread with the similar issue.
https://pinside.com/pinball/forum/topic/roadshow-opto-issues#post-1941054

Here is what I added to the Pinwiki after having the issue:
http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#.22Jittery.22_Opto_Switches

Most likely the column 8 flickering issue has been solved with the new opto board. Column 8 not working at all was interjected during the troubleshooting process. Try the jumpers as mot suggested above. If that works then check the wiring for column 8 as I explained above.

Something else to consider that's specific to TZ ...

The clock strobes off the aux 8 driver PCB ... if there are ANY issues with that board, the ribbon cable to that board, or within the clock itself, you can get all kinds of switch matrix havoc.

With very few exceptions, every single TZ clock opto board (including the factory board) connects the opto receivers directly to the switch row returns, strobed off the column 9 strobe from the aux 8 driver PCB.

Imagine the havoc with phantom signals getting into the other switch column row returns from the various clock optos ...

Easiest thing to do ... if you're trying to diagnose matrix issues : unplug the clock until you have the matrix working properly ... then plug the clock back in and solve any more issues you have there.