Midway Double Play table project

Oldfrothingslosh

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Apologies for noob questions in advance. Hoping someone can point me in the right direction. Picked up a beat-up non-working cocktail table version of Midway Double Play that I am hoping to bring back to life.

When I got it home and replaced the stripped out power cord, it actually powered up, the monitor showed the little dudes running into the field, and for a full two seconds I thought I got a great deal and got lucky. Then the screen started flashing and went blank. Definitely looking like a pcb issue rather than monitor, since I can get graphics out of the monitor (see below).

Actions taken:
Cleaned edge connectors
Reseated socketed PROMs on the main board
Verified voltage on the power board
Pulled the PROMs and got the two sets of clean vertical lines (per the Midway Processor Board Test Manual)

At this point, with the PROMs in place, when I turn it on the game flashes 8 screens of moving bars and then either goes blank or shows some random graphics.

I read somewhere regarding another Midway 8080 game that it could be something to do with the reset signal and that grounding that might get around it temporarily, but I could not follow how to do that.

So, I guess two questions:
Any ideas on what to try next (noob to intermediate level)?
Anyone know someone who does repairs in the Columbus OH area who I could contact?

Thanks in advance for any assistance provided. It is a really cool table and I am looking forward to getting it sorted out (somehow).
 
Possibly bad roms or rom sockets hard to say with the information. That error could be a few different things. Have you tried putting it in to test mode and seeing what it does?

It doesn't sound like a reset issue because it's not reseting every second or so. If you want to test it you can ground pin 12 on the CPU.

If you can't find someone to help you out locally I can have a look at it. I don't have a cabinet but it should work fine on my test bench.
 
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Thanks for the response! Tried grounding the pin, but no change in result.

Do you mean test mode using the dip switch? I did try that as well, but it doesn't do anything different.

I can basically get 2 things - either the solid test bars when I pull prom H, or the 8 consecutive flashing series of vertical lines followed by a blank screen when I hit the reset (seems like it is running a test of some sort and then just stops).

Running short on ideas and not finding much online, particularly since it is the table version of the game.

Thanks for the offer to give it a look. May take you up on that soon.
 
When you put the board in test mode the lines should come up with both thin and thick lines and then after so many screens i believe it is 8. it restarts and does it again. If it's stopping then there was a problem. It does sound like it could be a ROM error.

If it was on my desk I'd stick my known good Space Invaders daughter board in it and the Braze Space Invaders multikit on it which would test the RAM and if it started to play then I'd know it was most like ROMs.

You may not have those. If not you can check continuity between the 4 ROMs. all the pins but one (the chip enable) should share a connection, check +5 and ground on them and look for busted or bent pins.
 
Did you try a new power supply?

I read the voltages seem ok, but I would want to swap that out just to verify bad power. As you said, it starts but goes down, probably as it heats up
 
Good to know how the test mode is supposed to work. It does the 8 flashes and then stops, so it may be failing the test. I reseated the roms before and all looked well, but I will test continuity this weekend.

This is my first Midway 8080 game so no extra parts to swap working roms or a power supply. Have considered buying another power supply board and 8080 board on ebay, but they are all untested so that may just be creating another headache.

Thanks for the responses - very much appreciated. Will keep exploring this weekend.
 
So a handful of updates and next question.

1. Could not figure out why I only had 3 roms when all of the documentation that I found indicated should be 4. Remembered reading something (at some point in the hours of researching repairs) about Midway numbering games, went back and took a closer look at the game logic board, and... turns out it is Tornado Baseball, not Double Play. The table version doesn't have the name on it anywhere, and I got the game as a project from ebay where it was just listed as Midway Baseball.

2. In a burst of excitement, ran to the man cave to try the test mode again since it is a different dip switch for Tornado Baseball vs. Double Play. Plugged everything in, turned it on, got a whole lot of nothing. Realized that I did not have the power harness fully plugged in, pushed it in, and the fan immediately shut off. That didn't seem good. Turned the game off and back on, got a crackling sound, a neat little flash of light at the fuse and a little puff of smoke. So, kind of not good.

3. Ordered more fuses and a conversion power supply, and discovered Hobbyroms and ordered replacement roms.

4. Put the replacement power supply in and the new fuse, and got back to where I was before with flashing bars. No more smoke or blown fuses, so sort of progress.

5. Decided to do the "no roms" test again to confirm that I didn't fry anything else, and got the vertical bars, so that was good. Put the roms back in and turned it on, and... holy cow, the little dudes ran into the field and started throwing the ball around. Actually got it to play a half an inning. Then flashing stuff, and back to its normal non working behavior.

So, I am assuming that it is a rom thing at this point. Progress, and seems so close to being ready to work.

The question at this point. From what I read, the board needs to be strapped to handle the kind of roms that I will get from Hobbyroms. Lots of confusing stuff out there about that process. Is it a matter of soldering wires to jump between points on the board? I found a post from Blinddog with some photos of the connections. Is that the best place to start or can someone point me in the right direction? It is version D of the board.

Thanks in advance for any assistance. The half inning was awesome so I REALLY want to figure this thing out.
 
My Rev D board is set up for a single ROM mod but I can show you a rev E which will look the same. If you are running 9316 ROMs which I think you may be there won't be too much to do just move S2. I would recommend replacing the ROM sockets also.

QtuWmpn.jpg


RatuAbq.jpg
 
Update

I have strapped the board to match the photos. Popped in the new roms and got no change in behavior. Pulled the roms to see what the board does on its own and where I got clean vertical lines before, I am now getting slightly polluted vertical lines and 3 horizontal lines. They are evenly spaced so it looks kind of cool, but doesn't really help anything.

So it would seem like something went wrong - either I didn't solder well or the board ain't liking that configuration.

Any ideas, or anyone experience this type of thing?
 
See below. Let me know if you see anything wrong.
 

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Blinddog - thanks for hanging in there with me on this project. There is a cap between the g and h sockets. So that needs to come off the board?
 
If you have the Tantalum Caps in between the sockets like the Red, black and pink ones here in the picture then yes they should all be removed. they will drag down your address line (A10 i believe)
 

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Another update

Great call on the caps. With those out of the picture I got cleaned up bars on the no-rom test. Put the new roms back in and it booted right up. Got to play an inning this time before it went haywire and started doing the window shade flashing.

I have rom sockets on the way - did not replace those yet. I am assuming that is the best next step in eliminating potential issues.

Progress. Slow and steady progress. Thanks again for the recommendations and guidance.
 
I hope that fixes it.

I have a motherboard on my bench that is basically doing the same thing. Passes the tests on braze multi, I can start it and usually play a couple games but then it will lookup. I have figured it it out yet.
 
Update

Sockets replaced. Not the easiest process. And, unfortunately, no changes. May try swapping out the processor with one from a backup board that I bought as a long shot. Beyond that, running short on ideas.

Leaning at this point toward converting it to a mame cabinet to play old black and white games. Hate to do it but cannot figure out the issues with the board.

If anyone has any better ideas let me know.
 
One more update

Well, success, just not in the way I had in mind. After a lot of messing around trying to bring the game to life, finally gave up on the board and turned attention to running the game using a Raspberry Pi and Mame.

Pi hdmi to vga converter to rgb converter to the original monitor, which has a great picture. Just need the ipac this week and it should be set.

Not the typical end to a project I suppose but happy to be able to play the game in its cabinet and on its original monitor.
 

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