When does the 40 pin connector look like where the driver plugs onto the CPU board? My Blackout had 5 of the pins broken on the driver that weren't making connections.

There were also a ton of cold solder joints at the connectors around the driver board and anything like that needs to be addressed first before changing any chips. I put new connectors for the 40 pin interconnect and the fixed all the others. All of those were removed, cleaned, and I made a tool to fix them. They were cut almost flush with the board so I 3D printed a spacer to put on the back side the thickness of the board plus the amount of lead I wanted to extrude from the other side. Put each one in the vice with thin cardboard on the jaws of it and it only takes seconds to fix them. It evened out all the pins and pushed through about 1/32" which made all the difference when soldering. There is still plenty of pin on the top so the connectors still plug in ok.

Robert

Well at least it may be easier to replace than an entire melted harness. A good reminder to everyone how important it is to add the two fuses on the Williams games.

They were soldered on my Pinbot and Blackout. I heated it with the soldering gun and had my son pull the one wire of each bridge while I heated it. Then used the solde wick to clean off the rest of the solder on the terminals. I had to replace the terminal on the wires but the bridges were fine. The rest of the mid was easy just adding the two fuse holders and a couple jumpers with the 1/4" terminals on both ends.

Any of the ROM, PROM, EPROM, or EEPROM need to have the code or be programmed with the code for your specific game. If you have multiples in a game each once is different and may be different sizes so you'll need the set. That is important since there could be different versions of the code/data for your game and if you just replace one from a different version then you can cause problems. Some games share portions of code so a few chips can work across multiple games. On the early Williams the flippers ROM could be the same shared code across several games with a game specific ROM chip.

ROM - Is a chip is usually mask programmed and ordered in bulk from a chip manufacturer with the memory (code and data) set forever. Some early ones had odd pinouts and signals so that is one reason you'll see adapters so newer chips can replace them. Many have the same pinouts as the others so they act the same.

PROM - Is a one time programmable chip. Once you program it is set forever.

EPROM - Like a PROM but you can erase it by uncovering the quartz window and exposing it to UV light. That way you can reuse it if you make a mistake programming or want to load new code for a new version or different game. After programming you need to cover that window. Otherwise exposing to light over time will start to erase it. They are usually reliable but depending on a variety of things like how good the original programming device was, how it was stored, and how well it was made they will eventually degrade over time. I think most were suppose to be good for at least 25 years. Some drop out sooner and many more are still working fine way past that.

EEPROM - Like a PROM but don't have a window or exposure to UV light to erase. They are electrically erasable. Think flash devices.

I'm sure there are probably some excellent Wiki entries or sites with a lot more details on the specifics on each if you want more info.

I usually remove the battery holder now and install NVRAM

https://nvram.weebly.com

Check the DIP sockets on the sound card. I was having intermittent issues with my Blackout and replacing the original sockets with quality machine pin sockets fixed it.

Those largebground planes can make removing parts a pain. I've had my son help with a second iron on the other side of the PCB for difficult ones.

That's what I used to think but it isn't always the case. I ran into a leaky diode for one of the lamps at the top of the playfield on my Blackout. It was odd but replacing the diode fixed it. The rest was over a dozen bad lamp sockets that I replaced.

Is your Blackout running original boards? If so what has been done to them? Has the 40 pin interconnect been replaced? What about resoldering cracked solder joints?

I think he is referring to the dual bridge board that a lot of people use. You do need to chop off the ends of the wires for that.

Nice to see someone make one with the .250" terminals to match what is on the original bridge.

That should go right in place of the original bridge and looks like a good solution. I usually just install a standard fuse holder nearby, plug one of the wires from the transformer into that, then make a short jumper with .250 terminal to plug into the original bridge. In-expensive and accomplishes the same thing.

One thing to watch out for is many games have those connections soldered after they were plugged in. You have to heat them up with the iron to melt the solder in order to pull them off.

I've added the fuses on PinBot, Blackout, and soon FirePower.

It looks like a nice option and I prefer not hacking up the original wiring. These look like an easy drop in replacement.

Totally agree but it really doesn’t take much extra effort at all to make it looks like it belongs. These new bridge modules look like a nice clean easy way to do so. I’d use these.

Recently I’ve run into an odd issue on a System 3 MPU in a Williams Hot Tip machine. The board is extremely clean and recently had a new 40-pin connector set and new DIP sockets installed.

The board doesn’t always boot. If I shut off the game and turn it back on it usually just comes up an plays normally without issues.

Read about the factory mod to the reset section of the MPU to remove c27, r30, and r40. Then add a 10k resistor. This board already has this mod done and appears factory.

Any other known reset mods for the System 3 boards or items to check?

I completely went through the driver and power supply as well. I'm going to go back over all the boards on the bench again just to be sure and will check the resistors and transistors in the reset circuit in case any are bad. I typically don't have to touch those but don't want to assume they are ok since it isn't consistent when booting.

After that I will probably try my spare power supply and driver to see if that happens to clear things up. May pop in a different 6800 CPU since that is an AMI brand and I've run into issue with their PIA chips. Seems odd that it is just the initial booting of the machine. Once it is up it runs fine.

I did install a Weebly NVRAM module in it and could try going back to a regular 5101 RAM to see if that makes a difference.

Also curious if anyone has tried to do bypass some of the bus drivers like the change in the later System 6 boards and if that applies and would be a good thing to do on the earlier boards like the system 3-4

It's looking like it may be just a flaky AMI 6800 CPU chip. Swapped it out and it seems better. Need to do additional tests tomorrow evening.

I’m in that group for most of my machines except for all the bulbs behind the backglass which I have swapped out for non-ultrabright frosted LEDs on many games. Stay with a shade of white to avoid color bombing.

I guess it is good to think about reducing the fuse size if you’ve really reduced the load. Just want to make sure the fuse is the weakest link. Don’t want any wires or traces burning up on the boards.

I can’t recall hearing of any LEDs failing shorted but on these older Williams have had to replace lots of lamp sockets. Many of those loosen up and cause shorts. Smaller fuse soul just open sooner if that occurs.

That is just like the fuse that was in one of the holders in my Asteroids Deluxe monitor board when I bought it. Luckily the 1N400x fuse downstream acted as the secondary fuse protecting the rest.

Did you replace the 40-pin connector on both boards? If it has never been replaced that really needs to be done to ensure it is reliable.

As far as not booting are any of the PIA chips, processor, or 5101 chips AMI brand? Those have high failure rates. If so I would start with the 5101 chip then the PIA chips. If I run into an early board set with those I’ll pull them all out to test and then put in sockets.

Just fixed a non booting machine due to a bad AMI 6821 on the driver.

Check the 5101 no matter what brand it is. The CPU and PIA are suspect if AMI brand.

The TL866II is a handy unit and well worth the price. The logic chip test function works good and shows what pins have failed on a chip if just a single gate is bad so you know what part failed. Has trouble with some open collector chips so it may flag those bad when they are not. I use a different tester on those.

In regards to EPROM chips that programmer works well for reading most EPROM chips and to verify against know images. As far as programming replacement chips it depends. Some of the newer low voltage EPROM chips and programmable devices are ok. However chips like the 2716 no and would not trust it to properly program those or any older device that needs 21V or 25V. There are mods that are supposed to help but I just use an older programmer for those early devices.

So that TL866II is a good device that I like and use but you have to understand and work within its limits.

Best ones would be the replacement 6821 chips from Western Design Center available from Great Plains Electronics. Too many fakes of the Motorola chips to recommend a source for those.

I ordered some from Digikey. Mouser may also have some.

One thing I’d like to find more sources for are the large 18000uf axial caps just used my last one.

When I rebuild these boards I replace all the scanbe sockets even if the current machine doesn’t use them. You get a finished board that looks great and if you happen to want to install in a different machine with a different ROM configuration all the sockets are already done. The extra sockets don’t add much cost and it doesn’t take that much more time to do them.

If it isn’t used you don’t have to. For me I want the boards to look as good as they work and prefer the clean look of new sockets and keep the option open for easily using them if needed.

I would rather clip them than leave them open and sticking up on the board. The way they are more likely that someone with their hands in the backbox will bump them and start shorting address or data lines together. While easier to remove the way they are, my desoldering station has no issues pulling those through and dumping out later. To me just leaving those hanging is the least attractive option and has the highest risk.