The board that Coyote has is a newly built board. I won't send out the board that Crash sent back until I get that board investigated. I got some additional (independently acquired) information from wallybgood that I have passed on to Coyote. The information correlates very closely with everything seen so far and conceivably explains everything that is seen. A single point of failure that explains everything is the most likely cause. Multiple points of failure are possible but not likely.

It is pointing more toward silicon rather than board traces but until shown to be the case this is not definitive. I need to find time at a machine and spend it actually playing the machine. I know that sounds crazy ... play a game on a machine ... but in my current situation I have to travel to a different site to physically access a machine.

Acknowledged. Always open to suggestions. If the suggestion cannot be implemented I will provide a reason why so that it can be discussed if need be.

Today I went to do some machine testing. A few times for a board I am working on. The board worked on my bench but three failures at the machine. The first failure was due to the +5V being +4.8V at the test point on the power board. The machine works fine but it's clearly at the edge of acceptable. I wanted to slip this board into the pending fabrication order but I think I'm not going to hold up the order for this board. It will go in the next order (or when it works properly).

I also did two other things that have piled up. Firstly I tested the high voltage of the WPC-95 AV board. No surprise it works. So the board works on the bench and in a machine. It's ready for fabrication with the correction.

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I also took the WPC-89 sound board that was giving Crash grief. I tested it in a Creature from the Black Lagoon. I played some control games (with the OEM board). I then swapped the board in and played about 10-15 games. No problems. So I am at a loss as to why it fails for some games and not for others. The next step is to try this board with White Water on the bench and see if I can reproduce the problem. I do like a good puzzle but I don't like a puzzle that does not reproduce and therefore does not give me any direction. Like a cold case murder.

I used a friend's White Water machine. Mine is packed up at another friend's place. In these times of extreme contagion transmission I am doing everything I can to reduce exposure risk to me and to them so I have not considered re-testing in a machine.

I have not put it on the bench ... yet. I need to set up my bench rig with White Water. That's the next step for this problem for me. I am hopeful that it will reproduce and then I can start doing some swapping to see if the hunch of the cause of the problem is actually the cause. If it does not reproduce on the bench then I will try to make one attempt at testing at a machine with the proposed change to see if the problem first reproduces (it should) and then disappears (maybe it will) and then reappears when going back to the original configuration.

Board fabrication order is in progress so I am less stressed and have a little time to look at other things. That DE CPU board will take quite a few days of continuous work to get to a stage where the schematic is transcribed.

So ... a little progress tonight. I'm not going to declare the findings as definitive because I only have a sampling size of one.

On a whim (or a hunch):

- Swapped the 74LS244 in U1 and U2 on my CPU board (good thing I build these with everything socketed) with a 74HCT244.

- Logic levels should be compatible and everything appears to work on the display but the sounds went absolutely crazy with just this change.

- Changed the Fujitsu 74LS138 with a Texas Instruments 74LS138 in U26 on the sound board. This reduced the level of craziness but there were still errant problems.

- Tried the 74HCT244 with an OEM board. Works perfectly.

- Put back the reproduction board. Reduced level of sound craziness.

- Swapped back the to the Fujitsu and high level of sound craziness.

- Swapped back to the 74LS244 on the CPU board. Everything back to normal.

Conclusion ... IC incompatibility / variance due to manufacturer and silicon type. HCT is logic level compatible but may not be fully timing compatible. I know I read somewhere about issues on Rottendog CPU boards that use HCT ICs and replacing the HCT family with the LS family fixes the problem. Rottendog uses HCT presumably because they are cheaper and more readily available.

My first suggestion to anyone encountering this problem is to make sure you have an OEM (original Williams CPU) board.

@ Crash - Did the machine(s) that exhibited failure have OEM CPU boards?

@ Coyote - I know the TZ is not OEM (green LEDs as ChrisH has noticed). I hope the results of any testing at other machines provide evidence to back up the conclusion I made above (on a sample size of one).

If you're looking for a power driver board I have them available. See https://pinside.com/pinball/forum/topic/dumbass-test-and-reproduction-pcbs/page/2#post-5485609 for image. Current board has native (on board) support for LM2678 (5A switching regulator). Bare is $100. Complete is available on request. I have one 1/4 built but got distracted by the Thanksgiving rush and it's been sitting there while I'm working on the DE board.

Related but also unrelated.

I was asked to repair a Rottendog WPC-95 CPU board that was not starting (failed POST - no blinking diagnostic LED). I found the cause (the PLCC socket) and fixed it. I put it on my bench and it showed display issues (page errors and RAM address errors). I left it for a bit to go work on board design (working to a perceived deadline).

I came back to looking at the board last night after thinking about possible causes. I took my reproduction AV board off the rig and put an original Williams board. Problem disappeared. Weird. The game software directly controls the SRAM for the display pixels (through the ASIC). So I replaced the new (Alliance) SRAM I bought with an original (pulled) SRAM from an original board. Works fine - i.e. problem disappeared. Then I replaced the original SRAM with an older SRAM I bought from GPE years ago. Works fine. Put back the newer (Alliance) SRAM and the problem came back. Conclusion: Alliance SRAM is the cause.

Yet an original Williams WPC-95 CPU board works fine with the Alliance SRAM in the reproduction AV board. The Rottendog CPU board has 74HCT244 and 74ALS245. The 245 is the data bus transceiver and the 244 is the address bus buffer. Of course, an original Williams board has 74LS244 and 74LS245. Since the Rottendog is not my board I am not going to do anything to it but it's almost certainly the HCT compatibility to TTL that is causing the problem.

So I guess I need to issue warnings about potential incompatibilities between Rottendog boards and my reproduction boards. This is good information to have.

I guess I could also offer a new reproduction CPU board to "fix" any compatibility issues. . Of course, I need to work on a WPC-95 CPU but that's a ways down my list.

Are you asking about the portable diagnostic test system (as seen above)? If so it supports all System 11 and WPC (89 and 95) machines. It's based on board set so any game using a board set is supported. It does support Data East but to a limited extent in that the special solenoid connectors (switch and solenoid drive) are ordered differently and the power connector is keyed differently (absence of a key in the receptacle will mitigate the difference).

Each of the small connector boards (8P8C modular to Molex 0.100" (2.54mm) or 0.156" (3.96mm)) is labeled with which connector in which board set that it connects to.

There is no support for the 8-driver auxiliary board connectors. I have some thoughts about how to support that but due to the differences in the way that board was used and the fact that the 8 drivers are separated into 2x 4 solenoids per header makes it not obvious. It didn't seem important enough to hold up the product for a low frequency failure point (except perhaps the tieback diode in STTNG).

Ah. You want correlation between boards and game. I intend to go back and update the first post with this kind of information but it can be overwhelming for a lot of people. There are several ways of doing this and it might be my turn to word things incorrectly.

It stems from a level of complexity and the ability to interchange boards.

For example ... games can be grouped into WPC-89 alphanumeric, WPC-89 pre-fliptronic, WPC-89 fliptronic, WPC-89 DCS and WPC-89 security.

The power board A-12697-1 can be used in any of those games but A-12697-3 can only be used in fliptronic and later games (-3 can be converted to -1 by populating the flipper relay area). The fliptronic board A-15472 can only be used in fliptronic and later games. The audio board A-12738 can only be used in pre-DCS games but there are two versions of the pre-DCS board. I could go on. It's a big matrix of compatibility depending on the game and there are a fair number of games that are supported. It gets confusing really quickly.

I do intend to go back and label which of my boards are equivalent to the Williams numbers. For example:

- WPC-089-PWR is equivalent to A-12697-1, A-12697-3 and A-12697-4.
- WPC-089-CPU is equivalent to A-12742.
- WPC-089-SND is equivalent to A-12738.
- WPC-089-FLP is equivalent to A-15472.

Doing the above will allow correlation with Williams numbers in the manual with the board labeling system I use.

When I reach a lower amount of work on my work list I will try to go back and do this. My work list has increased recently and I still have a board in design that I want to complete to send for fabrication. Once in fabrication I can take the time to do this (overlap fabrication time with other things - keep the pipeline full).

GPE has examples @ https://www.greatplainselectronics.com/products.asp?cat=32 of fuse clips and holders. The clips use the two pads at each end and the holder uses one pad. It looks like the clips are perpendicular to the fuse direction.

I am not sure this answers your question though.

That's a 5x20mm fuse holder. Only revision 00 boards supported a "combo" fuse holder layout. When I first started doing this I thought that it would be nice to support either 3AG or 5x20mm fuse holders. Turns out the hole spacing doesn't support fuse clips. I'm not a fuse clip fan but I understand that giving a choice for either fuse clip or holder is the way to go. So I changed the layout to allow either 3AG fuse holder or clips. You don't want a revision 00 as it needs trace correction to work properly.

On GPE you want part number 354101GY (Littelfuse 03540101ZXGY).

You can use any of the fuse clips listed there. They are all 3AG fuse clips. The difference is the manufacturer and the maximum current rating.

Yes. These are what I use. You can use RT424006 or RTE24006. The datasheet contains the decoding of the part number. The pin layout and spacing is compatible for all of the TE RT series.

A board fabrication order arrived more than a week ago but things have been busy. There were three boards of importance in that delivery but I have only managed thus far to get to two of them.

I just finished building and testing revision 01 of the WPC-95 AV board. With the correction applied it all works properly with no cutting and stitching/jumping required. Ready for consumption. Bare boards are available and include the ASIC daughter board. Completed board availability will be limited to the ASICs I have on hand. The ASICs can only be acquired from merchants that have a supply and that supply will likely eventually run out as (I assume) the ASIC is no longer manufactured. If I run out of ASICs I can re-stock but due to limited suppliers I can not guarantee future availability of this board. I don't expect a large demand for this board as Rottendog boards are still available from various merchants.

85 days after the ask from SilverUnicorn it's finally ready. That's your board there on my bench.

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I previously finished testing revision 05 of the System 11 CPU board. I ran out of stock due to unexpected demand so when I needed to re-order I opened up the board and added a few very minor things.

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• Optional daughter board for special solenoid trigger (switch) status. LED illuminates when the playfield switch registers as closed.

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• LED indicator for ~MEM_PROT signal. This is the coin door interlock switch. It is not part of the switch matrix and there is no feedback for it.
• Additional test points for ~RESET and ~BLANKING.

  boards_117.jpg

The initial post in this thread has been updated (with fancy new formatting) for new board status and availability and correlation between Williams board assembly part numbers with my board nomenclature.

Thanks to emsrph for pointing out the PinWiki tables.

I hope it is more obvious and helps address the questions that ibis raised.

The last board in that previous board fabrication is now verified. It's the 16x16 dot matrix panel. These dots are a little smaller but the larger block allows for better alignment. I also had some small prototype boards made to make absolutely sure I got the measurements correct before making the panel.

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I soldered in the blocks for the 16x16 versus using SIP sockets for the 8x8. Both the blocks still have the protective film which is the reason for the additional glare. The 8x8 is actually RED. The 16x16 is orange. I ordered a smaller than regular minimum quantity of these 16x16 blocks. The company I used allow me to violate the MOQ requirements due to previous orders and expected future orders. I had 20x orange and 20x white blocks made. Next up is to solder the white blocks into the panel but I had a block verification board made and am waiting for delivery of that. I test the blocks before committing them to the board because de-soldering the center 8x8 blocks would be a PITA if there's an LED that is out.

This is the size and alignment comparison. The 8x8 blocks are 1.9mm in diameter. The 16x16 blocks are 1.7mm in diameter.

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The slave boards are done and dusted (ready). The master board works except for the 8-pin high voltage connector so the revision 00 master board works with a low voltage Stern compatible power connector. The high voltage connector needs wire order massaging but I plan to revise the master board to fix this (as well as revise the P-channel MOSFET footprint). Also in the works is a potential "unified" dot matrix board but that board will have to use SMT so it's lower on the priority list. The master/slave configuration is too "fat" for use in machines that mount the dot matrix display to the front of the backbox insert (games such as Gilligan's Island and Black Rose). All games that mount the display behind the speaker panel should work fine with the master/slave configuration.

If I didn't mention it previously the master board has a variable resistor (pot) that allows display brightness to be adjusted.

Sorry. I should clarify. Being verbose can reduce ambiguity but can also strain reader concentration.

The unified board will use the 16x16 through hole LED blocks. The traces occupy most of the board underneath the blocks and on the back side of the board (rows connections on one side and column connections on the other). The only place to put components is around the edge of the board. The driving circuitry isn't complex but it is repetitive. The unified board will look much like the Stern LED board - blocks in the middle and SMT components around the edge. I think the Stern LED board is a 4 layer (> 2 layer) board. I have some prototype building block SMT boards that I need to experiment with but there's always so many other things to do ... and SMT is a PITA to hand solder. That WPC-95 AV ASIC is 120 pins of pain and suffering.

One major advantage of the 16x16 blocks in a 128x32 use pattern is that there is always a block at the periphery and therefore can always be accessed from the edge. In the 8x8 block case a large number are completely contained in the internal matrix and impossible to easily access from the edge.

Pros for a unified board:

1. Only a single board is required (less board fabrication costs and no inter-board connectors)
2. SMT components are cheaper
3. Can have the board partially assembled by fabrication company

Cons for a unified board:

1. SMT components are harder to hand solder (in case of not using a pick-n-place setup)
2. SMT components are harder to service / repair in cases of failure

Everything is a trade-off.

Yes. I think. As you've worded it. I define unified as "the master and slave are unified into a single board". The board is compatible with the standard 128x32 DMDs (dot matrix displays).

At a VERY high level ...

For Williams:

• CPU software writes dots into the DMC (dot matrix controller) SRAM buffer.
• DMC hardware reads the SRAM buffer and translates the "image" to a series of on/off signals on a clock to the DMD (dot matrix display).
• DMD aligns to the same clock as the DMC and displays the on/off signals on the display itself. Clock and logic is contained on the DMD.

For Data East/Sega/Stern:

• CPU software communicates with the DMC (presumably there is a communication protocol).
• DMC responds to or acknowledges CPU software requests.
• DMC software produces the dots that make up the image.
• DMC hardware translates the "image" as per Williams.
• DMD displays the "image" (on/off signals).

The DMD (described above) contains logic running on a clock that displays the image on the glass (the glass is just a bunch of dots in a 128x32 matrix). My master/slave operates the same way in the sense the master board contains the logic running on a clock that drives the slave display that is just the "glass" or LED block matrix in my case. Plasma display logic is surface mounted (either underneath the glass or on the back of the board).

"Unified" does NOT unify the DMD and the DMC as described above. It is unable to do that because Williams and Data East use a completely different method to drive the DMD.

I hope that clears up any misunderstandings.

Teaser. This arrived today.

I placed an order for parts and the package was shipped (FedEx 2Day) last week (Monday). FedEx seems to have "lost" my package and I'm not sure if they're using the severe weather as a reason. The package is on the west coast and only needs to go up the west coast so I'm not sure where the severe weather is on the west coast. I'm tempted to place another order for the components that I don't have needed to complete the board as the last tracking entry is from last Thursday.

Alas ... I still have to finish some other outstanding orders so this board is in the queue and I may not have an answer until next week. The issue for me is that I don't like not knowing whether the board works or not because I can't make any decisions until I have that information.

Revision 00 - make sure the basic board works (transcription of the schematic and layout is correct). This board is revision 00. The only significant thing on this board that is different from the original is that the 74154 (4 to 16 demux) has been replaced with 2x 74138 (3 to 8 demux). The 74154 is difficult to find in DIPW-24 (it is available as SOIC-24). The 74138 is readily available in DIPN-16.

Revision 01 - add features and enhancements (also consider moving some traces around to make space for components). There will not be anything major but I can considering things like support for Williams special solenoid configuration or the special solenoid trigger status indicators.

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