It wouldn't hurt to post pics of the p/f and insert board. The more eyes looking at this may find something else that needs attention.
(Topic ID: 206324)
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Bad Cats
Williams, 1989
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Williamsburg, KY
Quoted from GRUMPY:It wouldn't hurt to post pics of the p/f and insert board. The more eyes looking at this may find something else that needs attention.
Absolutely. I’ll post a bunch of pics tomorrow. Maybe one of you guys can see something simple that I am missing.
I’ll also check over that aux power board and interconnect board again.
I have been reading this post for the last few days very interesting. Thanks for posting. Not sure if you have already done that but here's one thing I would try. Get a magnifying glass and remove the power board and inspect it from both sides. Maybe some solder problems with cracked or shorting solder on the back. I had some bizarre problems on a High Speed once and that turned out to be the problem. It wouldn't hurt to do the same for the other boards as well.
D12 and D23 which are both associated with the relay are showing 2.8 v in diode test in both directions while in circuit. They both test fine (5.3-5.5) volts out of circuit. I replaced them anyways but the reading is the same.
Quoted from Yoski:I have been reading this post for the last few days very interesting. Thanks for posting. Not sure if you have already done that but here's one thing I would try. Get a magnifying glass and remove the power board and inspect it from both sides. Maybe some solder problems with cracked or shorting solder on the back. I had some bizarre problems on a High Speed once and that turned out to be the problem. It wouldn't hurt to do the same for the other boards as well.
I appreciate all the help I can get on this thing. I have looked at it so long I can’t think straight anymore. I’ll recheck all of the boards again.
I think mine was a broken flasher bulb I just did some board repairs and got going again. Sometimes you never know, it feels like. Mine was in the back box for the translight. Maybe take a look at yours??
Quoted from Buzz:I think mine was a broken flasher bulb I just did some board repairs and got going again. Sometimes you never know, it feels like. Mine was in the back box for the translight. Maybe take a look at yours??
Was the bulb itself shorted?? I’ve had a bad led do that. This thing is driving me nuts. I’m going to pull all the flashers out and replace them I believe. However I have two more shorted 2n6427 transistors in the mpu. I’m out of them so I just ordered more. Yay
I think so a transitor blew so it was obvious and it was on that part of the board. The bulb glass was attached but not attached to the housing.
Quoted from Buzz:I think so a transitor blew so it was obvious and it was on that part of the board. The bulb glass was attached but not attached to the housing.
I didn't know flasher bulbs can be that dangerous. A flashing time bomb. Can the same happen with LEDs?
I think anything can. I had put some fuses in a couple of times that probably lead to it. Once it blew I knew where to look and isolate. Not the best thing to do and was an accident it happened. But in power lines we put in a big fuse and wait to see something glowing or wire burns down. Then you have found the fault. Finding out anything is possible with electronics.
Everything looks clean and nice enough to my eye. There were a couple playfield areas that caught my eye but after zooming and looking closer they seem OK.
On the aux power driver board, test R9 and make sure it's in spec. It looks like it got cooked based on the poopstain above it. This is on the 50V rail just before it splits into the relay. That relay also looks cooked.
On the interconnect board, R9 also looks suspect since it's the only one flipped over. Unfortunately this board seems like it might be configured as game-specific, since the schematic (in my WW manual) is kind of generic and no values are listed for R1-R11. The values for R13 and R14 are called out, though, and yours look to be correct FWIW.
One thing I DID notice on your MPU is that most of the ROM stickers are missing, exposing the silicon in the window. I always understood this to be a no-no as light can corrupt the silicon. In fact IIRC, one of the ways ROMs could be erased and re-used back in the day was shining a light through that window? I doubt that's your issue, but if you're trying to vet down to a single known good MPU, I would use the stickered-over ROMs to be safe.
That's all I got right now... sorry it's not of greater use. I wish you were a little closer, I love puzzling this kind of stuff out hands-on. Well I mean you're not THAT far... but just enough to require day planning... so let me know if you get desperate/bored.
Quoted from goingincirclez:Everything looks clean and nice enough to my eye. There were a couple playfield areas that caught my eye but after zooming and looking closer they seem OK.
On the aux power driver board, test R9 and make sure it's in spec. It looks like it got cooked based on the poopstain above it. This is on the 50V rail just before it splits into the relay. That relay also looks cooked.
On the interconnect board, R9 also looks suspect since it's the only one flipped over. Unfortunately this board seems like it might be configured as game-specific, since the schematic (in my WW manual) is kind of generic and no values are listed for R1-R11. The values for R13 and R14 are called out, though, and yours look to be correct FWIW.
One thing I DID notice on your MPU is that most of the ROM stickers are missing, exposing the silicon in the window. I always understood this to be a no-no as light can corrupt the silicon. In fact IIRC, one of the ways ROMs could be erased and re-used back in the day was shining a light through that window? I doubt that's your issue, but if you're trying to vet down to a single known good MPU, I would use the stickered-over ROMs to be safe.
That's all I got right now... sorry it's not of greater use. I wish you were a little closer, I love puzzling this kind of stuff out hands-on. Well I mean you're not THAT far... but just enough to require day planning... so let me know if you get desperate/bored.
I honestly appreciate any help I can get on it. I’m going to go through and check all those flasher bulbs individually for bad ones as mentioned above.
I’ll put some tape over those rom chips and check those resistors tonight.
I pulled this board and tried it out in a taxi I just picked up. The taxi board was ate up with acid so figured why not lol. As soon as I put it in Q25 exploded. I cut Q25 off the board and the machine booted and played (minus shooter lane kick out which is controlled by Q25). The taxi completely works with a different board in it by the way.
Q25 is the knocker and the tiger flasher.
I have retested the resistors that looked burnt and they all show the right ohms
I unhooked the knocker and both tiger flashers and still the same. The knocker coil is not shorted or at least it checks at around 4ohms.
I am back to the original five transistors shorted on the lamp strobe section. Q51, 59, 61, 63, 65 I believe were the ones.
Something is touching or one of the lamp sockets are bad. Not sure but could you ohm out each socket instead of isolating each one. I would maybe isolate the back box lights that has stayed constant as you have swapped things around or did I forget. There has been so much movement, but I feel you are getting the isolation of the issue closer and closer.
Quoted from Buzz:Not sure but could you ohm out each socket instead of isolating each one
Is this possible? This sounds like a much easier task if it is possible
Quoted from jmountjoy111:I pulled this board and tried it out in a taxi I just picked up.
CPU ?
Quoted from jmountjoy111:Q25 is the knocker and the tiger flasher.
This is for Bad cats. Q-25 blowing up in Taxi is a Taxi problem. All this confirms is the CPU board works and Q=25 is burnt.
Quoted from GRUMPY:CPU ?
This is for Bad cats. Q-25 blowing up in Taxi is a Taxi problem. All this confirms is the CPU board works and Q=25 is burnt.
Sorry, yes the cpu
I thought maybe the Q25 was shorted from being used in the bad cats and just hadn’t popped. It completely exploded as soon as I turned it on in the taxi. But the taxi is fully working with another board in it. The Q25 never blew on it.
Quoted from jmountjoy111:I thought maybe the Q25 was shorted from being used in the bad cats and just hadn’t popped. It completely exploded as soon as I turned it on in the taxi. But the taxi is fully working with another board in it. The Q25 never blew on it.
OK this makes more sense.
Quoted from jmountjoy111:The knocker coil is not shorted or at least it checks at around 4ohms.
Did you check the diode for this coil to see if it is installed backwards or shorted?
Quoted from GRUMPY:OK this makes more sense.
Did you check the diode for this coil to see if it is installed backwards or shorted?
I had checked all the diodes on the aux power board. They all tested over 5v in diode test. They were all in the proper way. I replaced two that were associated with the relay because they read volts both directions but I think that has something to do with being in circuit with the relay? Each read about 2.8v in both directions
That pin 4 on U19 is the blanking signal for Solenoid 8... which is R45, predriver Q18 (which is surely shot too), and Q22. Check SR6 and make sure it's in spec on Pin9, compared to the others.
Solenoid 8 is indeed the BBQ, on the "C" side. "A" side is unused so there is no associated coil - unless a short is present.
At least these weren't all random, or collateral. Hopefully you're getting closer....!
Upstream, U19 is fed by the data bus from U28. U28 pin9 is associated to Solenoid 8, if you are tracing links upstream. The only thing further up from there as source is the PIA at U51.
Quoted from goingincirclez:That pin 4 on U19 is the blanking signal for Solenoid 8... which is R45, predriver Q18 (which is surely shot too), and Q22. Check SR6 and make sure it's in spec on Pin9, compared to the others.
Solenoid 8 is indeed the BBQ, on the "C" side. "A" side is unused so there is no associated coil - unless a short is present.
At least these weren't all random, or collateral. Hopefully you're getting closer....!
I hope so. The socket for the bbq flasher under the playfield looked like it was covered in some kind of brown liquid residue. Almost like it had dried up soda on it or something which is weird since it is in the middle of the playfield
The cheapest part always causes the biggest headaches. 
Good job on staying with it and some great advice along the way for sure. This has been very interesting, and I can't wait for it all to work.
Quoted from jmountjoy111:the bbq flasher under the playfield looked like it was covered in some kind of brown ... residue.
Sounds like it was too aptly named... 
Also, don't forget to check Q22 as well!
Ok so I replaced about everything. Half the pins on the 6821 u51 didn’t match the other 6821s in diode test so I socketed it and replaced it as well
Coils do not lock on but they don’t work still either. When I press start the relay clicks over and over and then stops.
The transistors for the lamp strobes are out of the game because they were all shorted
How do I check this relay? Should I be able to measure ohms across the bottom pins on it? Could it be bad?
Replaced the relay. 50v switched coils are not working. But at least not locked on. Fuses are not blowing either. None of the strobes lamps are working because the Q51, 53, 55, 57, 59, 61, 63, and 65 all shorted out.
And.... Q22 exploded
A little confused given all the tests / failures / changes. The strobe transistors: were shorted before. Have you replaced them and they all shorted again?
You said this board essentially worked and played fine in the Taxi, before putting it back in Bad Cats where solenoid8 fried everything... but IIRC those strobe transistors were still out at that time you tried it in Taxi?
I'd be curious if you replaced all the components (including strobe transistors) and tried it in the Taxi again, to maybe get all board functions working in a known good game... THEN put it in Bad Cats and see what happens...? Unless you already did that, I apologize... It's getting hard to keep things straight.
Quoted from goingincirclez:A little confused given all the tests / failures / changes. The strobe transistors: were shorted before. Have you replaced them and they all shorted again?
You said this board essentially worked and played fine in the Taxi, before putting it back in Bad Cats where solenoid8 fried everything... but IIRC those strobe transistors were still out at that time you tried it in Taxi?
I'd be curious if you replaced all the components (including strobe transistors) and tried it in the Taxi again, to maybe get all board functions working in a known good game... THEN put it in Bad Cats and see what happens...? Unless you already did that, I apologize... It's getting hard to keep things straight.
I’m sorry. It’s all a little confusing. This board worked in the taxi but two of the strobe transistors were removed from the board when it was in the game. I should be getting more of those in today or tomorrow. I will replace them all and put it in the taxi and test.
I will also make a detailed list of everything that has been done at this point and post in the thread for reference. I’m really thinking there are multiple problems with the playfield wiring itself. It’s been a frustrating game so far lol. I really appreciate the help
With all components mentioned above on the board replaced I put the board in taxi. It is completely functional except for lamp column 5. I replaced the transistor Q58 but still no change. The taxi some bad connectors from acid damage and I replaced those as well to eliminate that to. I change. So... the board from the bad cats is functioning completely minus that column.
Quoted from jmountjoy111:With all components mentioned above on the board replaced I put the board in taxi. It is completely functional except for lamp column 5. I replaced the transistor Q58 but still no change. The taxi some bad connectors from acid damage and I replaced those as well to eliminate that to. I change. So... the board from the bad cats is functioning completely minus that column.
I replaced the 7408 at u52 on the cpu and now the board is 100% working. I’m going to look over the bad cats pretty closely one last time and I guess put it back in and see what happens. It might be the morning before I can get it in there.
Quoted from Buzz:You deserve this pin to work. Good job staying with it.
Thanks. It has driven me completely insane. Lol. I’m sure it’s something ridiculously small that is causing all the problems that I keep overlooking
Quoted from Rondogg:So awesome to see this thread end. And kinda sad. Great job. You should put solved in the title.
I wish it were solved but I’m pretty sure that there will still be problems once I get the board back in the bad cats. When I put this board in the taxi to test it it is not exhibit any of the same symptoms that the bad cats did.
Problems like this drives me nuts too, I think about it day and night and have trouble sleeping. I would be reluctant to turn that bad cat back on with the newly rebuilt board installed. I wish I could offer a better option
I would be curious to see a picture of the pile of parts that you’ve replaced
Quoted from Platypus:Problems like this drives me nuts too, I think about it day and night and have trouble sleeping. I would be reluctant to turn that bad cat back on with the newly rebuilt board installed. I wish I could offer a better option
I would be curious to see a picture of the pile of parts that you’ve replaced
I am hesitant to try it honestly. I’m going to put it in the other bad cats with the worse playfield first. The only issue I saw initially with it was the locked on coils. As soon as I fired it up coils would lock and I shut it off. The board had those shorted transistors at Q22 and Q25 so after fixing that issue I may at least get the worse of the two working. I guess I’m looking for small victories at this point lol
Congrats on getting the board fixed! At least that really helps narrow it down.
Agree this is a pretty nervous situation to be in: you know something is likely to fail but not what. So here's what I would do:
- You have two BC playfields, right? Inspect them BOTH. Anything that looks suspect (or not-original-factory-work) on one, compare to the other. Hopefully it's unlikely that both were hacked up in the same way, so between the two you might be able to figure out what's correct.
- Same with the interconnect and Aux boards: make sure they both look the same, or at least pick the best one(s).
- When you hook up the board to test, do things modularly. Leave the sound unhooked. Leave the backbox light panel unhooked. Maybe even the displays, you don't need them just to press "start". Just to rule out any bad inputs or weird collateral damage.
- Thus far it seems like lamps/flashers are the source culprit. If you just want the game to "play" first, try removing all the flasher bulbs and such. Maybe one is internally shorted. Maybe there's more brown goo in a socket somewhere. Maybe just the action of laying hands on all of them will force your eyes to see something you missed before.
- If the usual suspects seem OK visually, don't forget to trace and inspect the wiring harnesses themselves. Maybe something got snagged or frayed, or chewed on by pests, and you've got shorted wires in a harness you would ingore 99.8 percent of the time otherwise.
At least by this point you've got confidence in your board and repair skills so if it does blow up again, you can take what's learned there and get back to square one, revise, rinse, repeat....
...you'll get this figured out, I'm sure.
And the game is fixed!
Both games had j4 on the cpu and j4 the aux power board plugs switched. They are both keyed the same and both have purple wires. I had gone over those plugs a hundred times but hadn’t looked close enough I suppose. If it hadn’t have been for taking the board in and out and in and out of the taxi I would have not noticed. I knew it would be something simple.
Man I really appreciate all of the help. Especially from goingincirclez and @grumpy. You guys put up with my ignorance for the past two weeks! Lol. Despite all the negative people on pinside this kind of thing is the reason I’m on the site everyday. There are still great people out there willing to tirelessly lend a hand to other people in need.
Quoted from jmountjoy111:Both games had j4 on the cpu and j4 the aux power board plugs switched. They are both keyed the same
Wow that is just crazy!! On both pins too! Nice find.
Quoted from GRUMPY:Wow that is just crazy!! On both pins too! Nice find.
The operator I got the games from is a super good dude but his stuff is all jumbled up. I’ve bought five or six games from him and they all had a variety of issues. Most of them had been in storage for over a decade completely untouched. At least he pulls batteries out right
Ah damn I was close - I thought it seemed like something was crossed and even mentioned harnesses with the same key pins. File this one away for reference for sure, lol
Oh well, I'm glad you got it going! No shame in the silly stuff, I once posted an OMG SOS about my Whirlwind when all I'd done was forget to plug the transformer in... Duh...
Enjoy catching cats! If that second one needs a home, even as a project, let me know.
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