Or so I thought. Turned the machine off last night. Turned it back on this morning, no sound. Left it on all day when I went to work, came home, started a game, and the sound was fine. Didn't lose hi-score or programming memory, so I'm assuming the batteries were installed correctly. Any chance the caps on the sound board (Bally Cheapsqueak) are flaky? I'd hate to replace them if I didn't have to.
Generly the battery back up voltage was 3.5 to 4.5 volts, do you know what the battery was that you removed?
How far away from the circuit board did you mount the battery pack?
I remember you said you mounted it on the side of the light box, believe it or not, if it's a little too far away, it can make a differance. I have heard that if it's overall a foot or more away, and depending on the wire gauge, it can affect the memory and over all working of the back up system on a pin.
Are the battery's fresh, should they be nicad and will they charge when the game is turned on? If they ger a trickle when the game is on, and you removed a rechargeable battey, and replaced them with carbon type batterys, that would not be too good for the batterys or the game..
It can actually kill the carbon batterys, and cause them to get hot to the point they can explode.
You could get a three or four cell pack like for a cordless phone, and put that in and it would work fine for you. Just get the pack that the battery size would be about a AA. and depending on what the orignal voltage was, keep in mind that each cell would produce about 1.5 volts, so a three cell would be about 4.5/ 5 volts. That should work good for retaining memory.
Caps have been known for losing there funtionality over time, but I wouldn't really go down that road just yet. Look at your back up power first, take a look on line at This old pinball you may find some helpfull info there, or you can call Marco specialties, or another Pin parts place. They can give you some insight as to what might be going on.
Ok Magic, read your post on the battery replacement. Did you replace nicads, with Nicads? Were they fresh and charged?
If they were not fully charged, it could be why there is a problem. Although the machine when on, should recharge the batterys, if it's not on long enough it can't charge the batterys enough. So when it's off the trickle they provide for memory will drag them down.
Or it could be a charge issue with the circuit that is supposed to charge the batterys when the game is on.
So again, if you replaced the batterys with carbon's? Get them out!
Find a cordless pack at wally world, find a way to charge them up before you put them in the game, and see where you go from there.
Nicads are kinda testy at times, they really like to have a full charge before being used.
They're standard, fresh duracel batteries. 3 of them, which should cover the 3.6v NiCad removed from the board. I've got a rectifier diode in the circuit to block the charging. Probably about 6" worth of wire between the holder and the original location, which according to most sources should be fine.
The sound works fine, unless I leave the machine turned off overnight. Especially now that I've figured out how to program out the "attract mode". Don't need the darned thing blaring away in the middle of the night all by itself.
Upon further evaluation, leaving the machine turned off for as little as 15 minutes seems to kill the sound (it can be heard very faintly), but after turning it back on, by the end of playing 1 game, it's back. You wouldn't think the sound would be dependent on capacitors, but I can't think of any other thing that would explain it.
What I have now is identical to what the majority of pinball owners have in place of the original nicad batteries, and is functionally identical to what Marco sells to replace the original nicad.
If the rectifier was blocking the power going to the memory, I'd lose all my settings and the high game scores. I'm not, so it's working correctly, therefor the problem is elsewhere. The rectifier is simply blocking the trickle charge from reaching the batteries. It's like a one-way gate, power goes out, but can't come in.