TECH: How to replace the battery holder on a Williams System 11 CPU board
I recently had to replace the faulty battery holder on my Whirlwind and went searching for Clay's article on this topic which as we know is LONG GONE. So, I made my own here:
http://johnsarcade.com
Here's the article with the photos:
This is the BAD battery holder I pulled out:
Here's some photos of the new battery holder:
I recently had to replace the faulty battery holder on my Whirlwind and went searching for Clay's article on this topic which as we know is LONG GONE. So, I made my own here:
http://johnsarcade.com
Here's the article with the photos:
My Whirlwind recently started acting up. I would get a "Factory Settings" message every time I turned the game on. This is actually quite common, it typically means the batteries are bad or there is an issue with the battery holder, etc. When the game is powered off, three AA batteries keep your settings, free play/coin settings, high-scores, etc. If the batteries are dead, or if there is a connection issue with the battery holder, you get this error and your settings are lost. The game resets itself back to factory defaults.
It's common for the batteries to leak and/or for the original cheap battery holder to be corroded. The original holder is not very good. If your batteries have leaked in this area it is CRITICAL that you clean up the acid properly or it could spread all over your CPU board. Acid loves eating up and following traces. I suggest googling how to do this, but you should do it! This posting is not going to cover acid clean-up, we are only going to focus on the battery holder.
Anyways, I pulled my Whirlwind's System 11B CPU board out of the game and removed the original battery holder by de-soldering it with my soldering iron and a solder sucker. When I removed the battery holder, I noticed that one of the terminals on the battery holder basically fell off from corrosion. So, this is why I wasn't getting voltage from the battery holder!
Ok, now that we have the old battery holder out, let's replace it with a new one and remote mount it.
I went to Radio Shack and picked-up a four cell AA battery holder, a 1N4004 diode, and some quick connectors. You'll also need some wire which I already had on hand.
The System 11 board wants three AA batteries, not four. You can use a four cell AA battery holder since they are cheap and easy to find. Simply place and solder the diode in the fourth cell slot with the band side connecting to the red wire side. See photos. This diode simply protects the batteries from being charged by the CPU board. The System 11 boards DO NOT charge the batteries by default but this is just an extra safety measure and you need to fill up that fourth battery slot anyways! This also lowers the voltage slightly of the battery pack so the game will alert you to change your batteries sooner than later (FACTORY SETTINGS) which is also good additional safety.
After installing the diode I made a "twisted pair" with my cordless drill and two wires. Basically, insert your red and black wires into the drills chuck and then twist them together with the drill. This makes for a very clean mini-wiring harness. I didn't have red and black wire on hand so I used green and black. I used green for positive.
Ok, after that I installed my quick disconnects to make it easy to unplug the battery holder if I ever need to down the road.
Then, after that, you just need to solder the negative wire (black) to the top right battery holder solder pad on the PCB and the positive wire (typically red, I used green since this is what I had on hand!) to bottom left solder pad on the PCB. And, that's it! You're done.
You can screw the battery holder somewhere in the head or on the light door, I just placed the battery holder in the bottom of the head. If you do that, just be sure to unplug the battery holder before moving your game if you fold the head down.
That's it! All fixed!
This is the BAD battery holder I pulled out:
Here's some photos of the new battery holder:

