FlipperFanatic -
Review Pinwiki - I seem to remember something about measuring the power supplies. Something about ground not being the same reference when measuring voltages.

Put a 50 watt light bulb (load) on the output and read the voltage.

Is there a source for a game IC? I am working on a corroded MPU board, and it is missing an IC labeled "C". I want to try this in Joker Poker. Thanks

I only have an answer about the post adjustment. If you remove the post under the slingshot cover at the top left, there should be two or three holes where the screw that holds the post can go into. By moving the post that little amount equals big changes in how the ball reacts.

I've always been a bit confused concerning liberal/conservative - for whom are they speaking? The player or the operator? Regardless - move it and see what you like best.

I’ve attached a picture from a Bally machine, but the Williams should be close. You can see three holes in the playfield at the top of where the slingshots are. Those holes are the post adjustment.

I should have been more clear. At the top OF the left slingshot.

3562B8A7-7E72-47D4-8D9E-E1EBE5479DEA (resized).png

Chuckwurt - Harbor Freight has a body and molding trim kit that may work. They are basically two pronged forks that slip under the cap of the buttons to then pull it up. Better than just lifting one side with a screwdriver.

Snowtrooper - Has this just started? If so, you have fish paper (insulation) breaking down, or the ground from the electrical plug opened up, or the grounding inside the machine opened up.

If this is happening all the time, then check to verify the electrical cord is connected properly inside the machine, and that all the grounding is attached properly. Make sure the electrical cord has the ground prong - sometimes people pull them out because they don't have a grounded outlet.

Don't ignore this issue - it will only get worse and can get somebody hurt.

I would try to replace the chip, but use a socket. It looks like you may need to stitch a few of the connections.

Heat sink
https://www.electronicsurplus.com/thermalloy-aavid-501200b00000-heat-sink-for-14-or-16-pin-dip-pkg-of-3

The pin on the lower left is not making reliable contact - it needs reflowed. And since you're there, you may as well reflow the other pins, too.

Timtim - strip off about an inch of the plastic on each side of the break. Use a piece of braided ground strap and solder it, about 3/8" on each side. If you don't have ground strap, use a piece of 16 or 18 gauge wire. It will take a bit of heat - use some flux, pre-tin the areas, then solder the wire/braid. Should be good as new.

Just a PSA: if you have the Gottlieb playfield simulator/tester, it does work for testing the lamp drivers with a NiWumph board. (System1)

I have not tried the switch simulator side yet, nor the solenoid drivers. I’ll try that in about two weeks and report back.

Put a piece of paper between the contacts for each switch. Go to switch test and verify switch 34 is open. Pull paper, one at a time, till switch 34 closes. That’s your problem switch.

If switch 34 stays closed with paper between all contacts, then you have a shorted wire or a bad MPU.

Bontango - check your math.

Without knowing what the other three resistors are, you can't say for sure what the resistance is. However, I agree that they used what they had to get to the correct resistance.

The big question has to be: Did it work?

Your total resistance for that chain needs to match what was in there originally. Therefore, they need to add up to 1000 ohms. As long as the wattage on each individual resistor is at least 2 watts, they will be fine.

I only see the one resistor value, Which is 100 ohms. The other three need to add up to 900 ohms. I have to assume they are at least 2 watts.

Find a 1000 ohm resistor or combination to get to 1000 ohms.

I don’t know what the effect would be for a resistance of 40% of what was designed.

You mean like this?

I’m not sure about selling it right now since I’m working on a bunch of System 1 machines, but if the price is right ( I have no idea what these go for) I might let it go. Not sure about how shipping to Canada would work.

Also, it does work with an Ni-wumph board.

image (resized).jpg

image (resized).jpg

I got it thru a Craigslist ad about 10 years ago. The guy’s dad was a distributor near Atlanta, Georgia and he was going through some of his stuff and thought this might have some value. I gobbled it up, and asked him to contact me if he found any other pinball related stuff. I never heard anything more from him, so I don’t know if this was it or he just didn’t want to mess with it.

I think ForceFlow also has one, or something similar. I remember asking him about it after o got it.

I think that replacement would be OK. Are you going by looks or because its bad?

Do you have power to the machine when you turn it on? Its a coil with caps on each side, along with an inductance coil to filter out noise.

https://www.ato.com/power-line-filter-basics-working-principle

Electrically it will work, but I am worried that the stem would not be long enough to go thru the mounting plate to secure it and still be able to reach it and turn it on and off.

Measure the height of the old one, or at least measure how much stem you need to clear the mounting and still reach the button.

Cheddar - I have not seen that, but it makes me think there's an issue with the MPU. Are all the diodes good in the switch matrix for the Kings and Aces? They are located away from the switches.

I'm trying to get a few System 1 boards going, and I'm following Clay's guide. From what I am reading, if any of the data lines from U1 are not pulsing, then U1 is bad, and that's the end of the story. (Also assume that the reset and clock circuitry has been verified good.)
The pulses are checked at TC pins 1 thru 13. I have a few boards where a few of the lines are not pulsing - so, I'm looking for verification that this means U1 is bad.

I have a handful of these boards, and if U1 is bad, any suggestions of what to do with the boards since the spider chips are unobtainium?

Mthomassio - thanks for the info. So, for the boards where I'm missing data lines out from U1 - how should I proceed in finding out whether its bad or if something downstream is loading it down? Do I lift a leg from U1 and check for activity?

I'm really trying to learn these boards and its hard to believe that I have 8 bad boards. (Batteries have all been removed, luckily only one puked.)

Thanks - I'll report back what I find - I'm planning to go thru all of them again and get better documentation on what I have for each board.

EddiePi - I have used the alive LED, and yes, there's enough voltage there for an LED.

Ok. I decided to work one board at a time on the bench. I’ve got a Joker Poker rom in it, and an external battery. I’ve got 3.5 volts at the RAM.

I’m using a computer power supply, solid -12 and +5 volts. At power up, power supply is good, but looking TC1-14, my reset signal keeps resetting. In fact, on the scope, it looks like a heartbeat, going from -12 to +5 about every 6 tenths of a second. The heartbeat pattern is also at Z2.

I’m not sure why the constant reset or where to look next. Any ideas? Thanks

I'll go ahead and do the changes you mentioned, hopefully today/tonight and let everyone know. I did look at the power supplies on a meter while testing, and they looked solid. I'll look at it with a scope to see if there's any noise.

Wouldn't you know it - a zillion resistors here, and I'm missing two of the three I need. I think I'll start on a different board tonight, and leave the reset resistors alone for now.

System 1 sanity check, please.

Does the reset signal on TC1-14 stay at +5volts after startup or is it a 5 volt pulse, dropping down to 0 volts? (It starts ant -12 volts.). I ask since Z2 is a pulse output device, and I only see a -12 to +5 volt pulse, then zero volts on my scope.

Thanks

OK - got reset going - bad Z2. Checking for data pulses on TC1, logic probe says I have all the pulses. I'm not getting any display activity. The ABCD inputs to Z30 are not active. I checked the CPU bus for activity - there's some, but for the most part, just a constant 5 volt level, with waveform dips to about 3 volts. I am thinking I should see dips to near zero.

Is it possible I have a U chip that is bad, holding everything near 5 volts? Should I start lifting legs of the chips on the CPU bus to see is anything changes?

What a journey - these are so different than Bally/Wms!

I forgot about that - I like that option better - easier to repair. Any idea on which signal line would be my best option to start with?

You can tell they’re sprung by looking across the inside of the connector and look at the height of the mating surface.

I agree with Sparky, your issues are due to the connectors. Repin them all, DO NOT try trifurcon pins.

I'm not familiar with sys 80, but it sounds like the machine won't kick out the ball due to the trough switch. Look on the schematic and follow each wire from the switch to the circuit board. With power off, read resistance from the leaf on the switch to the first point on the circuit board. You should get close to zero ohms. I think one of these two wires is not being felt on the circuit board. Once you find which wire does not have continuity, break it down into sections - from the switch to the first connector pin, from the connector to the first point on the circuit board. I suspect you have a loose wire.