Here are the tilts...

bally1 (resized).jpg

Also, go into switch test and check each one. See if you get multiple hits on one switch. ( bad transistor)

Hello fellow Robocop owner. A Tilt Reset is triggered by the Slam Tilt (coin door) switch.

The fact that you have other switch problems means that it could very well be related. Definitely do a switch test and see if there is a common link with the switch matrix.

Here is the manual.

https://www.ipdb.org/files/1976/Data_East_1989_Robocop_English_Manual.pdf

Find the switch matrix page in manual and write down the targets not working.

See what wire color is common.

Daisy chain broken or hanging on by thread yes.

Would not hurt to investigate the area of damage via the clamp.

Are you able to start a game despite no displays? If you try to coin it up , any sound?

I'm sure you are aware, Make sure to power off when soldering , etc.

Note what work you have done and go back through it.

It has helped me many times..

Board is in excellent shape. The discoloration is is from heat as it collects dirt.

You're on the right track, it sounds like a broken wire or broken off diode at one of the switches in column 6, as shown below:

Screenshot_20220529-181114.png

Do any of those 8 switches work? The pop bumpers may fire/activate, but not score (or they may not fire at all). You want to look for a break in the daisy-chain of green-blue wiring. You should have continuity from that wire at all those switches up to connector CN8 pin 7 on the MPU (where the green-blue wire leads up to, from those playfield switches). It's also possible for one of the diode legs to break off any of those switches, causing a similar type of problem. Check everything carefully, give a light tug on each wire and diode leg to make sure they aren't hanging on by a thread etc.

Screenshot_20220529-181759.png

It's most likely not a problem with any of those switches, but a problem with the wiring that connects them all together with the wire running up to connector CN8 (or a problem at the male or female connector at CN8).

Do you have a multimeter?

One other thing to check: the wiring and diode at the switch for the VUK (Vertical Up Kicker), it's also in the same circuit as the non working switches as well.

Here's the location of it, #45 on the switch chart:
Screenshot_20220530-184450.png

This one is cheap and it has all the functions you'll need. I'd be happy to instruct you how to use it, it's not too difficult.

https://www.amazon.com/Etekcity-Multimeter-MSR-R500-Electronic-Multimeters/dp/B01N9QW620/ref=mp_s_a_1_3

Sounds good.

Yep, CN8 is on the motherboard/MPU but there's a way we can rule it out. Once we get the meter, we'll go over the basics and start testing between the switches and CN8.

Do you have any alligator jumpers? Probably worth getting a few, as they will likely come in handy for testing. https://www.amazon.com/Electrical-Crocodile-Experiment-Electronic-Inspection/dp/B09TFSC4ZL/ref=mp_s_a_1_1_sspa

Perfect, we'll see what we can do then.

One other thing--the wiring you'll be looking for at the pop bumpers is not going to be at the activation switch (the switch that the pop bumper skirt activates). The green/blue wiring will be at the switch that's closed by the pop bumper assembly when it's activated.

Again--you're searching for 1-2 green/blue wire(s) at all 8 of those switches. If you want to, post a pic of each of those 8 switches--maybe someone with a keen eye will see something wrong/broken. A meter would make quicker work of it, but we'll get there soon enough.

Nice! Make sure the battery is installed, then plug in the probes (red in middle spot, black in right spot). Turn the dial to the little speaker/sound symbol as below (I added a little blue arrow to point out out):

Screenshot_20220601-213107.png

Touch the red and black probes together--you should get a beep from the meter when they're touching. When in that mode, you can test wiring from end to end and if you get a beep, you know the wire has continuity (the meter is sending a small amount of electricity from one probe to the other, and beeps as long as it makes it across)...so the idea is to use the meter to verify that the green/blue wire coming from the MPU at CN8 pin 7 is reaching all 8 of those switches on the chart.

Find those green/blue wires at each of the switches. You should have continuity/beep between the bare ends of the green/blue wire at each of the switches in that column.

For example: when set to continuity/beep test, you should be able to touch either probe from the meter to the exposed/soldered end of a green/blue wire where it connects to any of those 3 yellow target switches, and touch the other probe to the exposed end of the green/blue wire at either of the other 2 yellow target switches. You should get a beep when you do that. Keep one probe on the same wire and move the other probe to the other green/blue wire at the other yellow target switch and make sure it beeps. Then from a yellow target switch to the spinner, or to any of the pop bumper scoring switches.

You should continue getting that beep between any pairing of any of those 8 switches on the column, because the wire "Daisy-chains" between them. That's why you'll see 2 green/blue wires at several of the switches--one's going "to" that switch and another is coming "from" that switch to the next one.

The switch matrix is surprisingly clever yet simple when you understand how it works. You'll get there soon enough! For now--make sure you have continuity between all 8 of the green/blue wires at those switches.

Here's an idea (though I realize I may not be explaining this clearly enough, I figured I'd try anyway)--grab an alligator jumper and clip one end to one of the meter probes. Clip the other end of the jumper to the exposed end of one of the green/blue wires at one of the problem switches. Now you can simply use the other probe to test continuity from the seven other switches with the one that's clipped on to the other probe. If you get a beep from all 7, you can rule out the wiring between the switches. At that point, it'll be a matter of testing between the wiring at the playfield up to the backbox where that same wiring ultimately leads to the MPU.

Ask any questions you have, hopefully this all makes sense!

I checked out the pics--i didn't see anything looking out of place except for the pic of the VUK switch -- I don't see a diode anywhere on that one, but it could just be the camera angle. Take a look the and confirm there is a diode attached to that switch somewhere (compare with other switches to see what the diode will look like, and how it should be wired with respect to the banded end etc.)... Share a few more pics of that switch from different angles if you're not sure.

Screenshot_20220601-220505.png

Good work! It sounds like the wire is making it's way to each switch as it should. Continuity tests are also very helpful for testing lamps, switches, and fuses.

Next we're going to try testing the switch matrix on the CPU board. You need to get into the "switch edges" test through the diagnostics, then disconnect CN8 (switch matrix columns) and CN10 (switch matrix rows) from the CPU board. Next, clip one of the alligator jumpers to CN8 pin 7 (which is the male pin for column 6, where the green-blue wire connects when the plug is inserted). The other end of the jumper can be touched to any of the male pins on CN10. As you touch each pin, you should see the display show each of those missing switches get activated. The yellow targets, spinner, VUK, and pop bumper scoring switches. If nothing at all happens, try moving the jumper to a different pin on CN8 and try the same test again using the other side of the alligator jumper on CN10. If you get switches registering each time on every pin *except* for pin 7--then there's a problem on the CPU board.

Let me know what you find, or if you need further clarification/have any questions/etc.

One other thing--you should be able to clip a probe from the meter to a green-blue wire on a switch under the playfield and test it for continuity right up to connector CN8 pin 7 on the female part of the connector. Might take a few extensions using alligator jumpers, but you should be able to confirm continuity all the way from the connector down to the playfield switches. You had the right idea though, and confirmed continuity up to that point.

Oh--and did you find the diode on that VUK switch?

Just an FYI, Data East's MPU Version 2 machines just call it "switch test". They never used the word 'edges'. You got switch test, active switches, and bad switches as the options.

It can be quite a few things. First thing to check would be the transistor that controls that switch column, which is conveniently labeled on the switch chart I posted earlier. The transistor is located at Q50 on the CPU board:

Screenshot_20220603-203441.png

And here's the location of Q50 on the CPU board: Screenshot_20220603-203730.png

Just look above connector CN8 and you'll see the eight column transistors--they're also labeled on the chart above. Those red numbers over each transistor are stating which column they drive. So you can see on this chart Q50 controls column 6, just as the first chart said it would.

Now - you want to test the transistor for column 6 with your multimeter. Time to learn to use the diode test! Oddly enough, it appears to be the same location on your meter as continuity. The instructions included with the meter should tell you if you need to push a button to toggle between diode test and continuity. You may not have to do anything more than set it to that setting.

Once you figure out how to use the diode setting, you want to test each pair of legs with the red probe on one leg, black on the other. Then swap the probes between the same legs and note that reading. Compare those readings with one of the other 7 working transistors. For instance, do the middle leg red, right leg black. Take note of reading. Reverse leads on the same legs, take reading. Now do middle red leg, left leg black. Take reading. Reverse legs, take reading. Now try another transistor and take readings. They won't be exact, but they'll be similar within a certain range +/-. If you get consistent readings comparing working transistors, but odd readings from the suspect transistor, I'd say you found the culprit. Again, ask questions if you need further clarification--it's tricky to explain but this stuff should hopefully be easy in practice. This is very basic info I'm giving here, there are more specific instructions I can get for you later. Still, I think my method should hopefully help us determine what we need to know

Note: removing the board would make it much easier to test them, obviously. I'd probably recommend doing so since the measurements are kinda tricky to take in the first place, the solder pads for the transistors are pretty close together. Depending how the transistors are mounted, you may only be able to get good access to the pads from the back side of the board. You can take readings from either side.

Def sounds like a bad transistor for column 6 in that case. In fact, it may be internally shorted which could be the reason the meter was beeping when measuring between the pair of legs.

Now you have to decide if you're ready to try replacing that transistor on the board. I'll admit it's not necessarily easy to do, but it's not entirely difficult either. I would def recommend practicing on a junk board first and get the hang of it. Or send it out for repairs if you don't want to take the risk. There's lots of good videos that can demonstrate what you'll need to do. I can provide some tips and stuff as well.

Nice work so far!

You're welcome! Glad you were able to diagnose the problem. It was a good chance to learn how to use the meter. The only functions you have left to learn are measuring AC and DC voltages and resistance (the continuity test is actually a test for low/no resistance, but the meter can also be used to check the resistance of the solenoids and many other components that are in higher ranges of resistance). It has other features and tests, but for the most part that covers 99% of the meter testing I find myself doing.

Post the solution if you get the chance, I'd like to see if Q50 was all that's needed. Good luck, and be sure to post back with further questions etc, too.

The components and board are generally pretty durable. As long as your iron isn't way too hot and you don't spend too much time with the iron touching the board, you should be ok. You want to get in, make the solder joint, and get out. It takes a little practice, but it gets easier the more you do. Def get a junk board to practice on first if you can, just to get a feel for the process.

Nah, the board's got a little damage but nothing a couple small repairs can't fix by the looks of it. A couple of the legs can be soldered right to the pads they lead to if necessary. I'd like to see what the backside of the board looks like in that area. The lower trace will likely need to be repaired, since it looks like it's a shared trace for all of those transistors. You can check it for continuity to be sure, but we'll get there once you have the new transistor installed.

I think you should still be able to get this going. Just gonna take a little extra work.