Cryo claw is acting up on my demolition man.

Claw cycles 8 times at power on instead of 1 time like it should. Claw is not working in game and the diverter to guide the ball to the claw never actuates. Every once in a while when I turn it on it the claw only cycles once and the diverter works and the claw magnet will pick up the ball but will not move.

Test reports a magnet broken fault

Claw test mode results:
Left and right claw works in test mode and opto switches show switches reading, switches also work in switch test mode.
Magnet works in test mode.
Elevator hold switch (74) shows closed in test mode and shows open when the opto is blocked.
Elevator index switch (67) shows closed in test and does not change state when cycling the elevator in test mode.

This tells me opto 67 is not working, I pulled the elevator cleaned the opto and reflowed everything and no change.

I checked the connections at j1 and j2 on the 7-opto board and all looked good.

My question is how do I tell if the problem is with the opto 67 board or if the 7-opto board is the problem?

Is there anything else I should be looking at?

Thanks

You are correct, I don't know why I keep mixing up switch 67 and 74 when i go to look it up in the manual, I have it written down and still look at the wrong one

Thanks

Ok, so I had a few minutes to look at it tonight.

I checked voltage to the elevator opto board, manual states it should be 12V, I have 13.9V

Went to check conductivity from Pin 2 and 3 on the elevator opto board to the CPU board J207 pin 6 and J209 pin 8 and I found a problem. There were no cables attached to J207 and J209. There were cables plugged into J206 and J208 immediately above it. The manual shows J206 and J208 as NC, so I checked the wire colors on the wires plugged into 206 and 208 and they match the wires for 207 and 209. I also checked for continuity to the elevator board and they were the proper wires.

So the prior owner or the tech he claimed that worked on it plugged the cables into the wrong socket on the CPU board. I plugged the cables into 207 and 209 and crossed my fingers. Now instead of the cryo claw and elevator cycling 8 times at power on it cycles continuously, even if you do not start a game. It cycles like it does when you do the cryo test in auto and hold the enter button down, it just cycles non stop.

I put it back in cryo test mode and the elevator opto switch 67 still never changes state. I pulled the 67 opto board and the diode and resistor check fine so it looks like the opto is bad, this would explain the switch never changing state in test mode.

I doubted the opto switch not changing states would make the motor run continuously so I went to check the power to the motor for a shorted transistor.

Problem is my manual only goes to page 33-4 and does not have a schematic for the power driver board. Pin J-126-2 in manual only states " black red, sol. 18 drive, to EMI board"

Does anyone know where I can get a copy of the schematic for the A-12697-3 power driver board?

I want to check the transistor driving the motor and do not know which one to check without a schematic.

I looked on line and cannot seem to find a schematic.

Thanks !

Thanks for the file, I grabbed it last night. Been working a lot of hours so limited time to work on it but try to fit in a few minutes each night

Looks like Q40 is the transistor and it’s working fine and not shorted. I also put a logic probe on j126 pin 2 and it only strobes on and off when the elevator cycles. There is a brief pause between cycles. So I know this is working properly.

I also pulled the motor board and everything checks out.

The game is back to cycling only 7 or 8 times on power up and that’s it. It is not cycling non stop any more.

Going to try and get the opto ordered tonight and see If that resolves it.

Parts arrived yesterday and replaced the opto, problem solved.

Everything is working but it seems like the claw pauses for a second after the ball drops into the elevator before it goes to get it.

Is this normal?

Thanks !

Replaced a bad GI connector tonight with a new one. The old one was toasty and getting hot. Had the game on for about an hour and put several games on it with no issues and it went bad real quick. Game went dead, lost power to the DMD and GI; boards are powered up but the game is dead.

Have to start digging into it tomorrow.

I had a little time and took a quick look last night, flipped the switch and it powered right up. All voltages checked fine, I rechecked all of the connectors and found another suspect one and replaced it. I also took a good look at the z connector and it looked good and was tight, i mean real tight. For a while I could get it to reset when pulling on z connector wires. I used a punch down tool to reset the wires in z connector and it would no longer reboot when i messed with it. It still however has the classic WPC reset issue, once it is warm it starts resetting even in attract mode. This is a new problem and just started after I replaced the GI connector. I double checked the connector and it is tight an all connections are good and it is not getting warm. I also ran it with the GI connector unplugged and it still reset so I know it is not the new connector.

Funny thing is it will take up to a minute to reboot, but when it appears dead all of the voltages are good on the driver board even though there is no power to the GI or DMD and the CPU light is still flashing sometimes.

I am going to check the voltage on BR2 tonight to see if its dropping off and maybe eliminate the Z connector if I have time.

I plan on replacing the Z connector, just don't know if I will have time tonight.

BR2 was replaced in 2006 home use only since it was changed, I know it could still have issues but at least its not original. I plan on monitoring the voltage on this tonight to see if its dropping before the game resets.

Finally got around to working on it this weekend. I eliminated the Z connector, pulled the driver board and replaced suspect pins and re soldered all connectors. so far no resets after around 5 hours of power on.

The Cryo Claw is working about 90% of the time. Every once in a while it will pick the ball up with the magnet but the claw does not move after it picks it up. None of the buttons will let me control the claw movement it just sits there. After a few seconds the magnet will turn off and drop the ball back into the elevator. At this point the elevator just cycles non stop and the magnet never turns back on again. To get the ball out of the elevator I have to cycle power and when I do the claw picks up the ball and drops it on the ramp allowing the ball to travel back to the trough so I can start a new game.

I already cleaned the upper opts, but may replace them to see if this corrects this issue.

Has anyone ever experienced this before?

Everything works fine in test, it happens intermittently. I noticed the elevator was slightly rubbing the wires to the upper opto last night and they were moving every time the elevator cycled. I repositioned the wires and it has not happened again.

I may have a poor solder joint on the opto from the elevator moving the wire. I will pull it and take a look at it tonight.