I don't know what you are calling the Main board. There is a MPU and power driver board.

With power off, press on all socketed parts (U9, game ROM and CPU chip) on the MPU board. This is potentially a problem.

If it still fails, measure the voltage C31 on the MPU board, with power on. What is the voltage? If 5v is lower than 4.9v, then reseat J101, J114 and J210, as these are usually the source of low voltage that cause a WPC game to reset.

This is supposed to be 5volts. What were you using as ground when you were testing the voltages at the DMD? Best to wedge the one meter lead under the ground braid wire in the bottom of the backbox so you don't have to hold both leads.

I don't see how you came up with 7volts on the 5volt rail. That is why I was asking where you were using ground from. Ground braid I see is what you did do, that's great.

C(capacitor)31 on the MPU board. Still using the ground braid for ground, use your red meter lead and touch the C31 on (+) side, which you will see labeled on the MPU board. What does the voltage measure? Just wanted to be sure you see the same voltage on the MPU as you do going to the DMD or not.

Very unusual. Best to unhook J114 so it no longer sends too much voltage to the other boards until this is fixed.

Can you post a picture of the driver board? Also can you test the 5volt test point that is near J114 after disconnecting it?

Just my opinion here. I do not think that driver board repair kit you plan on purchasing will help. The kit is made to repair low voltage, but in this case, the 5volts is measuring too high. Even with that, there is a good chance to damage the board as what comes in the kit. The parts are quite difficult to remove without damaging the board.

So this is a very good step in measuring voltages to really determine where an issue may be coming from.

Ok. Thanks! That is still measuring too high. I can tell C5 was changed, and that happens to be in the 5volt circuit. So with that, likely the BR2 was changed, even though I can't really tell from the top view.

I ask now that you remove the driver board and take a picture of the backside of the board. I suspect that someone jumpered something wrong, most likely because of damage to the board after replacing C5/BR2, causing the 5volts to be too high.

No rush here. But before you remove the board, I had another thought.

Does the serial number label (back of the game or on the right inside of the cabinet just above the power switch) show this as a 120v or 220v game? If it is 220, then you'll have to change jumpers on the input of the transformer most likely. Some of the voltages you measured that are shown on the OP are starting to lead me to this.

But if it is 120v, most likely what I stated in post #19 will likely be the correct path.

Ok. It is quite strange to see some higher than normal voltages, not just the 5volts.

Next, need to see how the input is wired up to the transformer. Just follow that black and white wire from that power distribution box to the 9 pin connector going toward the front of the transformer.

https://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Early_WPC_Transformers_.289_pin_connection.29

The first picture is what we are wanting it to be.
pasted_image (resized).png

I think it is wired up for 220v, which likely is like this.
pasted_image (resized).png

I'm in no hurry since I should be at work tomorrow. That is assuming this new hurricane doesn't slam Houston this time. They sky has gotten a bit quite the past hour, but that may not be the end of it.

Good. You'll need a break from storms the rest of the year.

Thank you for jumping back in. So if it is set for 105v, what do you expect the jumpers to be set as since it is not on Pinwiki?

If the transformer is not wired correctly for 115 volts, then there would not be a need to remove the driver board at this time.

Also, the fuse in the power distribution box that is labeled 220v also has another label that states 4 amp. This fuse needs to change to 8 amp slo blo when set for 115 volts. So can you look to see if 8 amp fuse is currently in that fuse holder?

Well, this is odd. It definitely started to sound like the input was wired different than 115v.

Looks like we will probably will need the picture of the back of the power driver board.

Hard to imagine having a failed transformer in this case. Can I bug you for a picture of the transformer?

Any chance your meter has low battery indicator on? That can cause some strange measurements at times.

Yes, please. I think you only need to plug in J101 and J102 on the right side to measure all the voltages on the board as you did in the 1st post.

Oh, I forgot the top left J112 does bring in the other 12V for optos and motors. Can you go ahead and connect in everything on the top of the driver board. Actually, you probably could go with all but J114.

TP2 is now 5.02v which is more like it.
What are TP1 and TP8?

Kinda feel we need to measure the AC voltages coming in from the transformer to the driver board next for a few of these higher voltages.
TP1 18.6V, normally about 13-15VDC
TP6 90v, normally about 72VDC
TP7 27.1v, normally about 22VDC

Probably best to rest on this for tonight.
Not really sure if the meter/battery had anything to 5v reading over 6v, but seems that way, but the other voltage measurements did not improve as I would had hoped.

I hope we hear back from ChrisHibler or DumbAss on other thoughts.

C2 is on my list to say to change so that doesn't happen here, but really should find out what really is going on with the other voltages first. So either have a driver board or transfomer issue here. Checking the AC voltage from the transformer should narrow this down.

One less thing. Great.

Also test the resistance of R224, the big white rectangle resistor that is just to the left of R260.

Test good. Thanks.

Do you have J112 plugged in at the top left?

So I think we are still back to the transformer. I am now wondering, are the right color wires are on the backside of this connector that are going to these pins? If not, then it would not be set up for 115VAC input. This is a reimport game afterall. So far, everything we seen pictures of, show it is done right, except what we hadn't seen yet.

pasted_image (resized).png

Arcade can you tell us what color wires are on the other side of pins 1, 2, 3, 7, 8, and 9?

Looks like another good schematic for Pinwiki.

I doubt it left the factory that way. I would believe someone else had worked on it for the owner. What the owner did not say if it was running off a step up transformer for a period of time before the game was coverted over to run off of 120Vac.

Another scenario would be that pins 4 and 7 broke at the crimp and someone repinned those two and got the pin locations confused, especially if a schematic or picture was not used as a reference.

Yes. 78V is much more reasonable now. 72V is pretty common on WPC games.

We thank you for your patience. Hook up that shit and play ball!!

How about pressing on all the socketed ICs on the MPU board? Probably a good time to reseat all the ribbon cables at all the board connections. I think it is 9 total ribbon cable connections in T2.

Might be good to reseat the other connectors on the DMD controller board as well. There is a power connector that brings in 5v and 12v to this board.

If that is helping, may test the voltages on the DMD power connector disconnected/connected.

Wouldn't hurt to test them all since it really is only 5 voltages there.

-112v, -100v, Ov, Ov, 5v, 12v, 62v

Can you remove the ribbon cable (while power is off) from the sound board only and see if the DMD still acts up?

Excellent. progress. So the DMD also is not acting up right now?

I probably should had asked that the 5v/12v power connector be removed.

Sure like to see what the DMD is showing.

It looks like a RAM issue on the DMD controller board, but it is ok without the sound board ribbon cable plugged in?

You have to post the video to YouTube and then post the link on a Pinside post.

Then I have to say the 6264 static RAM at U24 needs to be replaced on the DMD controller board. Can you try another DMD controller board to be sure it does not reappear?

You can try another working ribbon cable. So the one connector obviously will not be plugged in since T2 does not have a fliptronix board.
2019-02-02 14_20_45-WPC ribbon cable to reseat - Paint (resized).png

It's only 9:30pm. You need sleep?

I never had a MPU ever cause the DMD to do scramble like it was a RAM issue. Though, I never had any of my reimports wired wrong either. That could have damaged something on the MPU, which also could explain that sound board issue as well. A lot of information is passed down the data lines.

So the MPU is the next to try tomorrow.

Yes, sleep, if you must.

Oh I see!!

I was working today. I'm mowing my mom's yard tomorrow. Free on Saturday!!

Happy early birthday!

It is not a PIA. It is a 6809 CPU chip that is the 40 pin IC on the MPU.

Were you able to reseat U9? Takes a special tool to remove it.

Willing to try another MPU board in the game? I would. It looks like it could be support chips to the top ICs that may be causing the issue, if it is the MPU, which sure seems like it.

Those are for the switch matrix.

Correct.

mine are too. Everything you swapped already leans to the MPU.

You could "Get the CPU" (T2 reference) and swap into the working board and at least prove/disprove that as a possible failure.

This is a very unusual failure.

Enjoy!

Excellent. And yes it did. I was hopeful for the transformer being corrected, would had solved it all. Always seems to be something new.

Hope you didn't bend a pin

I would send it out for repair to ChrisHibler over buying a new board.

That is definitely an original problem. Not something I don't think I can repair without having it in my hands. No chance that U9 socket is not damaged?

I hope you are not looking at a Rottendog MPU.

Last thing you want to do is do anything while power is on. If you happen to short the switch matrix to any other voltage, you will find it difficult to locate a replacement part.

I had the misfortune of working on Rottendog boards for others who do not.

So changed some under the playfield when the game was on?

What LEDs are lit on the PDB and MPU? Maybe blew a fuse on the far upper right on the PDB.

This did happen on a Fish Tales I worked on this past Thursday. While the game was on, I pressed on the MPU socketed parts a bit and now it seems solid. You may have to even try that at the ribbon cable connections as well.

May try wiggling the DMD power connector. Especially Cherry DMD there usually are broken solder joints on this DMD power connector.

Time to be sure the correct voltages again at the DMD power connector.

Those voltages look great. Yeah, you may have to press on ribbon cables and the MPU parts while power is on. Difficult to tell where the issue could be again. At least it looks like the game has booted fine. May even try bypassing the sound board ribbon cable connection (disconnect with power off) to see if that gains anything.

I would think if the game ROM is corrupt, it would not even boot up.

Probably one of those times I wish I was in front of the game. I can't seem to think straight on this is not normal.

Have you pressed on any parts yet on the MPU and the ribbon cable connections while power is on? Might be the best bet in finding it if it a connection issue.

The FT that I talked about recently, I had to push in one corner of the ASIC chip to get it the DMD to work correctly.

I think you will find that the chip is $70+.

I think I understand the game is going in attract mode, can play a game, just bad DMD display? If so, the game actually is booting but playing blind.

Now I am wondering if your game might have had the default settings restored as if the batteries were removed. Yeah. Need to get your DMD working again so you can get passed this step.

Actually 3 of us keep saying that a blinking D20 means the MPU board booted up. It doesn't matter that the DMD is blank. It really did boot up.

Just making it clear is all.

This is where it gets interesting.

I have seen this in the past before, with a game I worked on the past that had batteries on the MPU. When I pressed the ASIC chip, it caused the default setting to be restored. For what seemed like a brief period there was an issue between the ASIC and RAM losing communication and ended up resetting the RAM. Yes, indeed. I helped to cause this issue when I asked to press on the ASIC chip.

You can't tell that it reset the default settings since the DMD is not working at the moment, which is why you feel the game is not booting, even though it has.

If you were able to press the far left coin door button, it would reset the game and go into attract mode.

So, after reviewing everything closer, you still have your original problem with pin 7 at the DMD measuring 12.90v. Normally this is 12 +/-.25, so the highest this ever should be is 12.25v.

So with the current DMD controller board in the game, can you test pin 7 at the DMD and TP3 on the driver board again? If TP3 is 12.90v, your driver board has an issue.

I think your DMD issue and your coin door issues are going to be related to this high 12.90v.

So can you test the other 3 coin door buttons? Need to see whether problem is with one or all 4.

Now it seems pretty important to measure the 12v out of both DMD controller boards that were being used, whichever game they may be in currently.

I don't have access to.the schematics, but I think it is pin 2, mirrored of what it would be at the DMD power connector, which is pin 7 there.

You could measure it at the DMD if that is easier for you. There is only wire I'm between so you will have the same result.

Can you measure the 12v on the other DMD controller board you were using to test with? Just making sure that was not also damaged since it was in the project game.

Does the other DMD controller also measure around 12.90v in the other game? Trying to see whether there is an issue in the game or only on the DMD controller board.

I am concerned of the 12v at J604 pin 7 going to the DMD on both DMD controller boards.

Seems it should be the 2nd pin from the other end of the connector.