How do I install a battery pack on a williams pinball board

[David P]

I have an external AA battery pack for a Williams system 11 game I want to desolder  the old battery pack that is on the board and solder on the new one. The new pack only has two wires a positive and a negative and some kind of a resistor.
My stupid question is does the positive wire need to be tapped in to every positive on the board where the old on board pack came off and the negative also to every port or does it just go to the last two posts and what might the resistor be for?

I believe John did this mod on his Whirlwind board I can solder just not sure if I need to make a bunch of jumper leads from every positive and negative terminal on the board or if the circuit completes it self.

sorry for stupid question

[KennyL]

Vid has some amazing guides on Pinside.  I found a post where he talks about the battery pack in his "bulletproofing Williams system 3-7" thread.  I imagine most pinball boards are similar.  Since the batteries normally complete their own circuit, you don't need to bridge the holes left where the battery holder used to be.  You just connect the battery pack positive to the first positive spot on the board and connect the ground to the last negative spot to complete the high score/setting battery backup circuit.

https://pinside.com/pinball/forum/topic/vids-guide-to-bulletproofing-williams-system-6#post-582663

[John's Arcade]

I took a photo of mine. I hope this explains it all:

CLICK FOR BIG:

http://johnsarcade.com/images/whirlwind/close_up_1.jpg

[KennyL]

So, is that resistor just a "zero ohm" resistor used as a jumper to fill the last battery slot, since you only need 3?  Or, what's in John's photo kinda looks like a diode.

[John's Arcade]

So, is that resistor just a "zero ohm" resistor used as a jumper to fill the last battery slot, since you only need 3?  Or, what's in John's photo kinda looks like a diode.

It's a diode. A blocking diode to fill in the last slot for safety.

I did this in one of my videos. Go checkout the Black Knight video.

[Netropolis]

Thanks John,

This will actually help me with my pinbot too!

[David P]

Thank you John that's AWESOME I have an actual 3 pack so wont need the diode that came with pack thank you John for the explanation..cheers!

[KennyL]

Well, the diode might not be a bad idea if it's really there for the reason of blocking reverse current.  But if it's just for filling the slot so you don't put 4 batteries in and over-power the backup circuitry, and you have a 3 slot pack, then it might not be needed.  I don't know enough about the board to know if it really requires a blocking diode for reverse current, but I imagine if it did it'd be on the board already.