Manufacturer: Midway Games
Released: 1993
Designer: ?
Added to my collection: January 12, 2012
Current Condition : Parted Out for a my MAME Machine


This game is still in my collection...but, now, it plays a lot more than NBA Jam.

There are exceptions to every rule, and the one I've already made an exception to (with Family Guy) was the "no game in the arcade that was made after 1985" rule.

It's no secret to anyone who knows me that I hate basketball. I find it boring and repetitive. But, oddly enough, I've always liked basketball video games--and the best of the bunch is NBA Jam. When I was working at MicroProse, we had several video games in our break room. At first, it was just Atari's Red Baron (a game that purportedly figures heavily in the founding of MicroProse) and a couple of games from the short-lived MicroProse coin-op division--F-15 Strike Eagle and B.O.T.S.S. At some point, though, someone added an NBA Jam to the mix.

And I was hooked.

Pretty much every day, I'd play at least one game (often quite a few more). And it was one of those cool, competitive, multiplayer games you could just never get enough of. I never really actively sought an NBA Jam--it's huge and there's only so much space in the arcade. But, when one came along at an insanely low price, I simply couldn't resist.

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My Machine

I make it a habit to check the local Craigslist page pretty much every day. Honestly, it's the best source of coin-op deals in existence these days. You can find some incredible deals up there, and right in the neighborhood for the most part.

That said, it seems like the best deals seem to come along on the days I forget to check Craigslist.

My friend Jim (who, I'm happy to say, I helped to get hooked on the coin-op collecting hobby) found an amazing deal--two 25-inch, 4-player NBA Jam cabinets for a very low price, only 20 minutes from my house! The owner had no idea what condition they were in electronically but, based on the pictures, they were in good physical shape. Needless to say, we jumped at the deal. I let Jim have his pick of the two, and he opted for the one that we could see had no monitor chassis, but had the better cabinet of the two. (The one I got had a control panel that was not attached...looked like it had been torn off at some point.)

Turns out, my machine wasn't in terrible shape at all. It is complete except for the power supply. There is also one button that sticks. (There were two sticking originally...but for some reason I had a brand new orange micro-switch button. Not that it was odd that I had a button, mind you...but it was odd that I had an orange one since none of my games has orange buttons.) Assuming nothing else is wrong with the game, this will, by far, be my cheapest game--around $60 with the new power supply and button. I've even got an ace in the hole--a set of NBA Jam boards that are tested and working (in case the boards in the new game are dead). I had those boards in my 60-in-1 game before I turned it into a multicade, so I know they work.

As you can see from the before picture, the game wasn't in terrible shape when I got it--just dirty. It turns out the cabinet was originally a Teenage Mutant Ninja Turtles machine (you can see a bit of the original side art peeking out on the sides). That's why the control panel was taken off--to hack into it to add buttons. (TMNT uses 2 per player, NBA Jam uses 3.) A few wood screws and the control panel was secure. I didn't even need to use my own screws--I found them among the usual detritus in the bottom of the game, along with $2.54 in change and 19 tokens.

Getting the Jam Jammin'

It's now official--this is the cheapest game I've ever bought.

As mentioned above, the game was missing the power supply and needed a couple of buttons replaced, but that was all that appeared to be wrong with it. I got the power supply (a standard 15-watt switching power supply from Arcadeshop) and installed it. That took some doing. In a JAMMA machine, all of the wires coming off of the main wiring harness are the same colors no matter what JAMMA game you're dealing with. Unfortunately, the wires in my cabinet had been hacked and spliced to make them longer, and whoever did this didn't bother using the same wire colors. Therefore, the wires from the harness didn't match the colors in the NBA Jam manual schematic for the power supply connections. That meant that I had to trace the wires back to their splices and see which color was witch. (No big deal, but a bit of a pain.)

Then, there was the AC power. The schematic showed that the two AC power wires were Violet. I had no violet wires. The only two I had that were possible candidates were a Red/Black wire and a Black/White wire coming off of the rear door interlock switch. I knew they were PROBABLY AC power, but I wasn't positive.

This is where my "name that conversion cabinet" skills came into play. Since I knew for sure that this cabinet used to be Teenage Mutant Ninja Turtles, I looked up a manual for that game. Turns out the AC Flow Chart proved that my suspicions were correct--those two wires were, indeed, the AC power. So I connected all the wires and fired up the game.

Nothing. Blank screen. No sound. Sigh.

I checked all the connections and tried again with the same result. My initial assessment was "bad boards." Luckily, I had my back-up boards handy. I hooked the harness up to the back-up boards and the game worked! I did a little "I got a $60 video game" dance. Then, I removed the boards that had been in the cabinet and permanently installed my back-ups. I fired up the machine.

Nothing. Blank screen. No sound. Sigh.

I fiddled for a while and intermittently got it to work, but most of the time I got nothing. I figured that my hacked harness had a loose wire somewhere and was pretty much resigned to rewiring the cabinet with something not so hacked.

Then, I had a flash of insight. I remembered that incorrect voltage can cause the game to malfunction. If there isn't enough power to the board, it can either not work at all or reboot frequently. So, the next day, I started fiddling with the knob on the power supply that increases and decreases the voltage output. Sure enough, when I turned it up a bit higher, the game worked like a charm! I once again did the "I got a $60 video game" dance, and was just a smidge proud of myself that I figured out the problem. I think I might actually be learning something about this stuff after all these years!

The last thing I had to do was get the monitor re-capped--the image was "rolled" at the top of the screen, and there was a weird wavy oscillation on the left and right edges of the screen. I got an estimate from a local guy who does repairs, and he said he'd do it for $105. That seemed a bit high to me, but I had never re-capped a monitor before. Then, I watched a video online that showed how to re-cap a monitor and said to myself, "That looks way too easy to pay someone $105 to do it." So, I bought the cap kit from Bob Roberts for $15 (shipped) and set to work soldering. And it was. It took me about 6 hours, total, but I got it done.

The cap kit fixed the rolled image, but the waves at the side of the picture were still there. I figured it was the high-voltage filter capacitor that sits next to the monitor flyback that was the issue. (This cap isn't included in the standard cap kit.) So, I picked one up for under $9 (shipped) at a company called Digi-Key and replaced the old one, which was bulged and corroded. It helped the problem but didn't fix it entirely. For now, I'm leaving it as-is--it's playable. I suspect that I'll need to find a new flyback and replace that to take care of the wavy picture once and for all.

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NBA Jam Technical Info:

DIP switch settings:

NBA Jam has two 8-switch banks on the main game board. You can find the settings at KLOV, along with links to PDF files for the game manual and schematics. Options can also be set from on-screen menus when the game is in setup mode.

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More NBA Jam Info:

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