S-2000 Cpu problems when removing green battery

[Foster]

There are 502A and 502B boards, and there are a couple of Technicial rework bulletins from IGT for tthe 502 boards.

Now that I think about it I did the rework on my 502A then removed the battery.
Thats when I noticed the reel tilts on the 502A, put  the jumper in no more reel tilts.

[novao65]

I have reached my limit for now, I tried the sizzlin 7 board today and it reel tilted on the third spin, I then checked the door optics and they were fine, so I have to set it aside for a while before I go nuts, If someone has some of the green batteries for sale I would try to solder them in and see if that would help. I tried to check all the connections that foster said and the only thing that I have done to the machine is run a jumper wire on the counter connection to stop all that ticking.
Anymore item that you think I can try let me know.
Thanks for all the help

[novao65]

I know it has been a long time, but I found a green battery and installed it on one of the boards that reel tilts and it now works fine. played it all night yesterday and not one problem. I guess they must need the green battery on them, cannot afford to buy new batteries for 25 dollars a pop so I have 5 boards that work so will leave the batteries on the boards. If anyone can give me an answer why some boards will work without them let me know.
I have been working on the boards a lot since I first posted this I am slow and could only get out into my workshop  in the last few weeks.
Thanks for everyone's help.

[Foster]

If they are The Enhanced MPU you can't remove the green battery at all
I removed only the negative terminal and it would not even boot. Re-soldered positive back in and all was fine.

On the 50x boards you can remove the green battery.
This is what I found out about the 50x series it helps to solder a jumper to reconnect the 2 solder pads on the board for the negative battery terminals
That should solve the reel tilts on the 50x boards. I am one that discovered the issue and many argued that soldering the jumper was not needed.
Mine started the reel tilt issue within minutes of the battery removal and stopped as soon I rigged a jumper in place to test my theory about the 2 points not being connected after the battery was removed.

Easy way to ID the 2 different styles of boards
the Enhanced MPU you cant see the green battery because it is under a legacy board (sockets for the game chips)or what is known as R board (flash type), the CMOS battery can be easily changed and located near the handle for the mpu tray and you will see a gold alloy trace around the board.
the 50x series board the game chips are located in sockets on the board, and near to the i960 chip with the cmos battery in the corner

Edited to correct terminal designation for future readers.

[novao65]

Thanks for the info Foster but I do not understand the jumper as the negative has on connection and the positive has two so if you could show me a picture of the jumper that you use  it would be helpful. The board is a 502 and I had a jumper between the two negative connections and that did not work. I now have a spare board that works if I need to trouble shoot a problem and I have two boards (502) without the battery that reel tilts, so I guess I will use them for parts if I ever need them. I do not know if this is important to this problem but my candle bottom light will not go out, I plan to replace the back plane but do not know how hard that will be, are the any instruction anywhere that tell how to do this and do you think this could be part of the above problem, the rest of the machine works great.
Thanks for all you time and help.

[Foster]

Oops I meant install the jumper on the positive solder pads.
I was posting from memory

And since you broght that up I also think I undid the negative to test if removing the battery on the Enhanced MPU was possible instead of the positive unless they totally changed the battery design.

[novao65]

This is my final cure for the removal of the green battery. Since I had four boards that quit working after I took the green battery off as I posted above I had a game that the green battery was starting to leak so I replaced it with this Empire Battery for a GTE3000 Portable phone. IT is 3.6 volts,80 ma and works fine. I double sided taped it to the board. I have played the machine about 40 hours so far and everything is working fine and I do not have to worry about leakage.
 Since this battery is 8 dollars and not 25 dollars it suits my budget much better. I think this is a cheap fix if needed. What do you think.