There is a separate small board in the upper right of the backbox that does those switches. They are not on the switch matrix.

Congrats on the fix! Thanks for posting the resolution!

THAT took out the switches? Is it still working? As when you short out one of those coils/tips for the driver 8 board, that's usually indicative of the tie back line breaking free, and the next time it energizes that said coil, all hell breaks loose again.

The tie back line is a yellow wire tied into the up or down coil for the rear drop target.

glad you got it fixed!

All the canon home and mark switches are in switch column 9 (which is one more than most machines have) which is operated by the Aux Board on which you have been working.

I would first check other switches in rows 2, 5, 6 and 7 (the rows the canon switches are on) to make sure they are working to rule out a CPU board problem. You can do this by looking up the switch matrix in the manual, entering switch edge test and pressing any switch in those rows and making sure they register.

Assuming they register correctly, the problem is most likely on the Aux board column driver. Column 9 exits the Aux Board through J5, pin 1. It is driven by Q12 (TIP102) and Q1 pre-driver (2N4403).

As above, I would pull that board, check all the transistors again, pre-drivers as well, and see if you can find the issue. I'm guessing it's another transistor, as I haven't seen the IC fail in any of these instances for this driver 8, but have only dealt with a few.

Look for hacks too, as this board is sometimes hacked to shit. I had one where all the pre-driver transistors were removed, and one pad on each were all soldered together - and it was working!!

For anyone with a STTNG, I recommend anytime you have the PF up to lastly check the tieback wire each time before you put it down given what can happen if you power this up when it is not a solid connection.

Check your board traces for breaks too.

Measure this with the board out and not connected in the head. They should measure .4 to .8 or so for each leg, and should be consistent in readings for all tip102s. If there is a replacement, sometimes they are slightly different, depending on the manufacturer.

I believe this is with the red to the ground (center) and the black to the outside, but it might be backwards. If you get anything else outside of the readings you are getting from the majority of them, check in the manual to see what that leads to and you should find your issue.

If the other switches in the row and columns work, I would not look to the CPU board yet, especially considering you have been messing with the aux board.

Do all the solenoids on the aux board work now?

Once you confirm the other solenoids on the Aux board are working, to further troubleshoot switch column 9, use a logic probe to see if there is a pulsing signal on pin 19 (latched output) and pin 2 (D7 bus) on U1 on the Aux board with the machine in switch edge test mode.

If you have a pulsing signal on pin 2 but not on pin 19, U1 is bad. If you do have pulsing signals on both pins, look to Q1 and Q12.

Ok, I had to pull up the manual at this time over coffee . There are 4 switches in column 9, which is clearly a possible problem. Are the mark switches working for the cannons? Check those in switch test. I'm guessing they are not, or at least the right gun mark is not.

IF the left mark works, and the right not, you have a broken wire in he switch daisy chain, either from mark left to right gun home, or incoming at right gun home.

IF neither mark registers, you have a column problem, which again could be a column 9 driver 8 board issue OR a broken wire off the first switch for this column from the driver 8, people often overlook this when a complete column or row is out, and go straight to assuming a board issue, but it's possible as is an easy first check.

IF both marks register, but not the gun homes, well, you got me, and that would almost have to indicate two separate issues in column 5 and 7, and a broken wire in the daisy chain there for each, or both micro switches simultaneously failed, which given these both started at the same time, is incredibly unlikely.

Check those and report back.

Just a note, you really can't measure the voltage on the switch matrix accurately with a DMM. Column 9 that you were tracing is pulsed on and off 60 times per second which will drive a DMM crazy. The good news is it sounds like it is pulsing which would suggest the aux board is working.

On a negative note, seems unlikely that 2 diodes would fail simultaneously but heck, they are cheap and only take a few minutes to change. Keeping the fingers crossed...

I can't recall, is there a cannon test mode in the tests menu? If so, that is usually how you can test some of these outside matrix switches I believe. I'd have to check on mine, but if you can go there, that would indicate when the switches are made. Check the marks there if this exists.

As for diodes, how did you test them? They have to be out of circuit for a true test, which means one leg disconnected at least.

I had the same problem and I am not nearly as technically proficient as you guys, but I changed out the coil sleeves and not only are the cannons stronger, they have no trouble finding home. I'm just throwing this out there....

The coil sleeves could not possibly have any connection to a switch issue. If that did resolve your issue when you swapped them, you likely had an intermittent issue with a wire that was moved in a way that made better connection or something like that.

New sleeves only provide less resistance for the plunger to move within the coil.

ugg, you should have mentioned you were doing that. If the transistor is fried, it usually locks on the coil and shorts that. Then if you replace the transistor or board, without changing the coil, the bad coil will then take out the new, and this vicious cycle continued until you fix the board AND coil issues. This is what makes STTNG a pain, the use of this board (for a large part).

Check the diverter coils, and the drop target ones (I believe those are the only coils controlled by this board, don't have manual in front of me), to see if they are in range (at least one is not), and pull the board, and check and replace any bad transistors.

When you get the new stuff make sure all the transistors are good on the board, and disconnect those coils, and make sure the resistance for each is within range. THEN power up.

No, they all have connectors, just disconnect and check. They can't be in circuit is all.

Yep, just unplug J3 and J4 from the aux board and you can measure coil resistance on all the coils controlled by the aux board.

You posted the above 5 days ago. When you were here, were the home switches working again? I'll play with mine and figure out how to test those mark switches as well.

This time, try powering it up without J3 and J4 connected to see if the switches work before trying the solenoids.

With J4 disconnected?

You might want to clear the resolved mark for the topic.

Are you sure about Q12 ?
in your picture I see wire:
'brown/white' = under divertor top = Q16 and
'black/white' = under divertor bot. = Q15

check diode next to Q15 and/or Q16 on 8-driver-board

I believe the drive-transistors and all connectors are kept the same to match the schedule.

8-driver RD vs BW-215.jpg

well done, have fun playing STtnG, great machine !