Title says it all. I picked up two bad cats projects the other day. I have one of them up and running but it blows f4 and f2a. I am struggling with it so I figured I’d ask for help.

On start up several coils lock but not all at once. It starts with the knocker. If I unhook it the dog house locks. If I unhook it the five bank drop locks. If I unhook it the garbage can locks. If I unhook it the outhole locks etc, etc...

The aux power board relay clicks over and over. The flashers light when it clicks.

When I press the start button the coils release but when the trough outhole attempts to launch the ball into the shooter lane several of not all of the 50v coils fire. None strongly. It won’t kick the ball into the shooter lane. After a few seconds f4 and f2a blow.

The sea food motor turns on start up but about half way it kind of grinds to a stop. If I unhook it it doesn’t change the coils locking.

Any help will be greatly appreciated.

Tp1 +5 is 4.94
Tp2 gnd is good
Tp3 +12 is 12.05
Tp4 -12 is -14.93

Is the -12 too low?

How would I check to see if there is any ac on the dc side?

I switched the meter to ac and tested the power supply. The meter starts with numbers but quickly counts down to read OL. Then it starts that same cycle over.

The 5v test point on the mpu reads 5.01.

Maybe it is just my meter.

All reading were the same with both power supplies.

When I test the wall outlet I read 121.7 and it holds there.

On the test in the video I had the black lead into the ground braid at the base of the head before it enters the cabinet

I really appreciate the help btw. This thing has been driving me nuts lol

I’ll have to go pick one up.

I haven’t got a different meter yet to check the ac voltage but bumping this up for any other ideas

I moved this board set and playfield to the other cabinet because it was in better shape. The issues followed of course. But I guess it at least eliminated power from the cabinet to the boards as an issues right

I have basically used two complete different sets of boards on this thing and moved it to a new cabinet. I am going to start checking the playfield again for anything obvious. I would love to just isolate the problem a little

I had already tried both board sets in the game. The other mpu boots up but a resistor started smoking. The problem was consistent with both power supplies and both aux power boards. I try the other playfield and see if the problem persists. I don’t know why I didn’t check that lol. I’m struggling today

R82

I hooked it up with the other playfield and the coils locked instantly so I guess that eliminates the playfield

I just tried the game ROMs from the other mpu and the same thing happened

Should I try boards from my whirlwind to narrow it down?

That’s what I was thinking to.

So any ideas what to look at next

It’s made my head hurt too.

One side of the a/c relay on the aux power board is shorted now. I had replaced it already when I first got the game so it has shorted it again.

Pins 8, 6, and 2 show continuity. It should only have continuity between 6 and 2 right? Or am I just reading that wrong

The pins on the back of the relay. They were numbered on the top of the relay. Odd numbers on the left and even on the right

AE173C18-11AB-4BCD-9A6E-374D2FD86082 (resized).jpeg

I’m thinking something else is causing the relay to give. The relay was bad when I got the machine. I replaced it and It’s now bad again. Plus it’s bad in the other board too. So what could cause that?

I can take it apart this evening probably and get you some pics of it.

If the relay is shorting out like that is it possible that the problem still could lie in the playfield itself and the when second playfield the already shorted relay caused it to lock on a well? I don’t know if that makes any sense but I mean playfield one shorted the relay. The relay caused the coils to lock. Playfield two the has coils lock due to the shorted relay caused by playfield one?

It is blowing f4 and f2a fuses. I’ll read through the post. I’m going to check the playfield overthis evening pretty thoroughly once again just to be sure

I remove the relay from the board, and there is no continuity between pins six and eight with the relay removed. When looking at the underside of the relay, even pans are on the right side correct? I just want to make sure I’m looking at this right and not telling you all something incorrect.

Also, it appears that while in the board there is continuity between pins six and eight because of the jumper at W6. Is this correct

OK I just wanted to make sure. Now that it is out of the board, there is no continuity between pins eight and six. I have continuity between pins one and three and pins two and six only. When following the traces on the backside of the board it appears as if they are connected through the jumper at W6.

With the relay removed from the aux power board and it reinstalled in the game with good fuses there is no continuity between f2a and f4

Sorry I must have misread that the first time. I just checked and f1 and f4 are not showing continuity. F4 shows continuity with only f5 and f6 which at the flippers and both 50v allowed. That’s normal right

Sorry for the suspense lol.

I turned it on. The fuses do not blow.

With the relay out. I tested the power at f4 and f2a. There is .05 mv dc power at f2a And 77 volts at f4. Are those normal readings considering the relay is out

No insert lamps work either. Are those tied in to the 25 volt?

I have 42 volts to both f1 and f3

I checked the ac voltage on f2a just to make sure. It read between .015 and .020 volts. All other dc fuses read OL.

I have 8 volts at the single fuse in the backbox

At the bridge I have 19 volts tot he purple wire. 8 to the blue and white wires and like .052mv to the black. Isn’t it ground

I put the aux power back in with the relay in so I could describe exactly what happens when turned on.

When the machine turns on The five bank drop and dog house coils lock. (This happened with both playfields which makes me think the problem is in the boards) The insert lamps flicker and the seafood motor turn but neither like they are supposed to. If it continues until f4 blows then the knocker locks on (which is weird cause it should be on f4 correct?). If I press the start button before the fuse blows the coil stop and the game plays. But none of the insert lamps, or switched 50volt coils work. When a switched 50v is triggered several coils pulse but none strong enough to eject the ball. I’ll shoot a video and post it

This is the sequence with both f4 and f2a fuses in the game and working

This is what the machine does with the f4 fuse completely pulled from the game. The knocker and outhole lock on. This thing is possessed.

It’s crazy. You see in the video that once the ball is in play, All lights stop.

I figured the ipdb would have it but it stops when it gets to the schematics

The first set that locks on (five bank drop and doghouse) are yello and violet. The second set that locks without the fuse (knocker and outhole) are brown

Ok that makes more sense.

Yes give me just a second and I’ll try that.

Yes there are flashers in the backbox

The cat and woman motor in the back box work fine.

I did the solenoid test. As it cycled through the test the cement resistors 82-89 got super hot and smoked so I shut it off. During the test each time an a side coil was to fire all a side coils fired. Just like during gameplay.

Yes the flashers worked.

I just checked sr16 above those resistors and about five legs on that are shorted together. Could that be the culprit or and effect??

The outside legs of Q51,59,61,63,and 65 all show continuity

I can unhook the insert board and try.

I need to replace all of those transistors correct

That was tested with the board out of the machine

I will get those in there tomorrow. I wonder what would cause five to short like that

I replaced those transistors and decided to test out the other board that I had tried in the machine initially. Not the exact same transistors but four transistors in that set coming off of j7 were shorted. That has to either be the insert board or the playfield causing this correct?

This game is so frustrating! I took the other board and replaced the transistors in it that were shorted and put it in other machine. The coils on that playfield locked on too. On top of that one of those lamp row transistors shorted again lol. I can’t win for losing wth this thing

I was going to report some coil resistance reading that I thought were pretty off.

These ohm readings were all taken with the coil in circuit but read from the lugs.

Yellow/violet 50v wire
Dog house: 2.2 ohm
Five bank drop: 2.2 ohm
Three bank drop: 10.6 ohm

Brown 25v wire
Trash can: 1.3 ohm
Outhole 1.3 ohm
Knocker 1.2 ohm

All of those reading seem off. Most of those coils are 23-800. They should be around 3.8 ohm correct?

None of those have a diode. I was just getting ready to check the manual to see if they were needed

The manual doesn’t show any diodes on the coils. I have a ton of 1n4004. Should I just go ahead and put them on each coil anyway?

Were these readings acceptable coming from the bridge in the backbox?

Ok. I noticed in the manual that each coil had a labeled diode on the aux power board. I cut the wires on one and measured it (dog house) and it was now reading 3.8 ohm. I hadn’t checked the others yet but I will for sure.

I went through the insert board and checked for noticeable damage or shorts. I went ahead and replaced all the bulbs while I was at it. The relay connectors were fried. I replaced the connectors. I went ahead and reflows all of the pins on the relay to eliminate cold solder. I checked it and didn’t see any shorts. The game still acts the same with the insert board completely unhooked.

I looked over the playfield and could not see anything. There was one switch wire that was pinched under a flasher bracket and I thought for a second I had found it but the wire was not broken nor were the two shorted together. I removed it and moved on. I’m not really sure what my next step is. I suppose in the morning I’m going to check all of the coils out of circuit. Should I start checking the diodes on the aux power board for those coils you think

I’ll test them next. I’m just glad to be getting somewhere with this thing

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.

Here are some underplayfield pics

723907AE-5848-4396-A070-2B63A41225BB (resized).jpeg

83052769-83EF-4B30-93AE-8E008B909A90 (resized).jpeg

4BCE95D5-08BA-4FB4-AA54-4295A8FCD122 (resized).jpeg

C41EF09A-6D5F-4EB4-8E34-D5B9E6997604 (resized).jpeg

54CCD9BE-2BC8-4DC9-A4F4-0088DDCB4182 (resized).jpeg

Insert board pics

F1A63EE5-7F04-46A0-A3A3-D0D3961E3DFF (resized).jpeg

D0CE7C01-32CA-4F1A-98EF-8102A9D073E2 (resized).jpeg

A403A502-65D0-45A7-BABE-8E8209F7F6C3 (resized).jpeg

858BFD33-C146-485B-A466-8A29AF6568A4 (resized).jpeg

Here are some pics of the board set

D82BF9B8-C58D-42C2-A78F-1E74EC47A03B (resized).jpeg

26515EF7-6211-42C0-8BBA-D876EBD2B251 (resized).jpeg

F0CB167D-B176-4A4A-AD43-F124C6947B7B (resized).jpeg

2EFBE506-841B-4E72-A9EA-3A352F575B8E (resized).jpeg

647DB317-0873-49DF-9B10-1560CFC05E71 (resized).jpeg

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.

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.

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 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.

Is this possible? This sounds like a much easier task if it is possible

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.

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

With the insert board unhooked. U19 on the cpu has exploded. R45 resistor is burned. These control the bbq flashers. I unhooked the flasher under the playfield.

9E148C52-F7EF-45F7-AA6B-46BEB451B4C1 (resized).jpeg

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

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

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.

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.

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

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.

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

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.

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