Tom Callahan Pin Logic MPU game ROM's

Quoted from Quench:
Playboy requires system ROM "720-30" at U6, so go with option 4)

Quench as usual fixed my game! Installed that chip and game fired up. One thing I did notice with this "Mutha MPU", when the game is 1st powered up I get zero flashes on the LED. If I turn it back off and the on again, game boots as normal. It was doing this when last installed in an Eight Ball. Not a big deal as I got used to the double power up. But I'm considering selling this game with this MPU in it since my board repair guy has had 2 MPU's trying to get one OE ready for this game for 3 months.

#6 4 years ago

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tomdrum

Quoted from Quench:
By zero flashes do you mean the LED is locked on?

The Callahan board has 2 red LED's, one showing 5V and the other 12V. Also has a green test LED. When it doesn't boot, just the red LED's light, nothing from the green. The problem is intermittent, today I had the game powered on for almost an hour. Now after sitting off for a hour it boots right up. I've started it 4 times since and it will boot normally.

#8 4 years ago

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tomdrum

Quoted from barakandl:
Sounds like just a connector issue than. If the 5v is lit the 12v most be good at least at the driver board, so i'd expect the problem to be connector pin at MPU J4. Or maybe on the other side of that 12v wire.

It was doing the same thing when it was installed in a different game. In both games the MPU J4 connector was re-pinned.

#11 4 years ago

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tomdrum

Quoted from Quench:
You mean when it doesn't boot, you don't even get the initial power-on flicker on the green test LED?

It did it last night again. All 3 light and stay lit. The green LED stays solid. Just powered it up this AM and it booted normally.

Post last edited 4 years ago: “grammer”

#13 4 years ago

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tomdrum

Quoted from barakandl:
If u9 is a MC6802, EF6802, F6802 or S6802 try changing it to a HD6802. If crystal start up is the problem the hitachi HD6802 CPU should work better.

It is a MC6802. Who sell the hitachi HD6802?

#15 4 years ago

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tomdrum

Quoted from barakandl:
If you don't have easy access to a hd6802p to try you can check to see if the cyrstal start up really is the problem. With a scope or maybe even logic probe or DMM on frequency test you can watch the "E" pin #34 of the 6802. As soon as the reset lets go "E" pin should pulse around 0.5mhz. If it is slow to start up or way out of time on the failed boots that is probably the issue.
Haven't seen a schematic for that MPU, but looking at pictures it appears the crystal setup is exactly what I tried and found to be unreliable at times with motorola CPUs so I can't expect that board to work any better.
If it turns out to be a crystal startup problem and you cant get a hd6802 you could also try changing the load capacitors, the CPU, and/or the crystal itself to see if you get more reliable boot. What value are the two capacitors in the pierce oscillator circuit near the crystal? You can try a range of about 27pF to 50pF. Fine tuning the load capacitors here may help. NPO/COG type capacitors are normally whats recommended to be used. The cheap ceramic caps drift big time with heat.

Thanks but that went way over my head! Changing a socketed chip, sure I can handle that. I pay people to fix my boards or buy new ones. Speaking of which, when will assembled Bally rectifiers be available AS-2518-18?

#16 4 years ago

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tomdrum

Lo and behold I found a hitachi HD6802p in a bunch of chips that I've had for years. I'll swap that in.

#18 4 years ago

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tomdrum

Quoted from barakandl:
My blank boards are manufactured in China. I have an order tied up hoping would get shipped before Chinese New Year and now the virus delay on top of that. Numerous items are going to go out of stock soon =(.

Ouch. I see the blank boards are still on the website. Are the components also missing? I think I bought a dozen of them in the last 18 months.

#20 4 years ago

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tomdrum

Quoted from barakandl:
If u9 is a MC6802, EF6802, F6802 or S6802 try changing it to a HD6802. If crystal start up is the problem the hitachi HD6802 CPU should work better.

Having minimal board experience, if I change out the U9 to the hitachi HD6802p, is that all I'll need to do? I don't want to hit a brick wall taking a working game and kill it by a chip change.

#22 4 years ago

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tomdrum