Remote Mounting A Battery Pack
|Here we have a Data East Pinball CPU, out of a Tales From
The Crypt. From a distance, the only real thing you notice are the
slight burn marks in the upper right quadrant of the board.
Everything works perfectly on this board, the game functions flawlessly.
|On closer examination, the CPU batteries are starting to
look ugly. The CPU appears to have never been removed until I removed it
tonight, and the zip tie around the battery pack looks original.... the
batteries are Vartas, and the game was built in 1993.
I've used a lot of Vartas over the years in photography, and I liked them because they were guaranteed to never leak, or Varta would pay the damage. Great batteries from Germany.
|This is a photo of the battery pack once removed from the
game. Nice and corroded, luckily there was zero damage to the CPU board.
Battery Acid is horrible when it gets on anything, and eventually an
acid damaged board gets ruined.
So, why remote mount the batteries? You can just change the batteries every year and never have problems, right? Well, if you *remember* to change the batteries every year, your odds are pretty good that your packs will never corrode, but even fresh batteries have been known to leak before. Remote mounting the batteries ensures that if the batteries leak, all you are out is a $2 plastic battery pack, which you can easily replace.
|Here is a shot of the back of the CPU board. Simply take your desoldering iron and de-solder the prongs for the battery pack. They come out rather easily.|
|Here is a photo of the primary parts you need for the job.
Everything can be had from Radio Shack, including
274-222 2 Position Interlocking Connector
270-391A 4 Cell AA Battery Holder
3 AA Batteries
Red and Black Connecting Wire
|The CPU after the battery pack is removed|
|Solder your wiring to the CPU board. Put the connector on
the other end of the wiring. I like to cut the length so I can carefully
route the wiring for the battery pack through existing wire loops
If you're doing this to a board with a perfectly good battery pack, you could always leave the existing pack in place in case you think you might ever need the pack - but most games I get have bad battery packs, and why replace a $5 part I won't use?
|I find a spot on the hinged light board large enough to
fasten the pack to. You can use velcro or double-stick tape, but I
prefer to use 2 small screws.
Note the 4th cell opening is used for the diode, which prevents CPU boards from trying to charge the batteries. Not all games do this, but I make the packs universal so I can use them in any game.
Install the 1N4004 Diode with the banded end towards the right (shown with the wires exiting on the lower right corner.
Crimp and/or solder your plug on the wires at the end of the battery pack. Note how you do it on one game and always do it the same way, so your packs are uniform and interchangeable.
|Carefully route the wiring through factory wire clips whenever possible.|
|A photo of the finished TFTC battery mounting.
Make sure to label the batteries, I replace all mine once a year, when I put the new smoke detector batteries in.
Replace the batteries with the power on to retain custom settings, high scores, etc.
|An identical pack in my Creature From The Black Lagoon.
I use these packs in all my games. The design is universal, it can be used to replace the pack in most any machine that uses a battery to hold the settings and high scores in memory.
Note: Working on expensive, delicate circuit boards with sensitive traces, difficult or impossible to obtain parts, and heat sensitive components is NOT for everyone. If you are not experienced with such types of board work, I suggest seeking professional help. myhomegameroom.com is NOT responsible for any damage to your pinball machines from performing these modifications
I strongly recommend the following individuals, and endorse their products.
|If your boards need repair, contact
Clive @ Coin Op Cauldron
(864) 238 1707
|If your boards are fine, and you want a no-solder approach
to remote mounting your batteries, seek help from
Steve @ Pingizmos
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Page last updated Wednesday June 13, 2007
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