Help with Bally 5000 Plus

[coffinails74]

I have a bally 5000 plus crazy winners and when I do a ram clear after I close and lock the door every thing is fine I can add up to the three coin max. Then when I press the spin the reels spin slow and will not stop along with a beeping sound. The win meter displays 3.3. 1 and also 51. The reels continue to spin until I reset the mpu. I have ran the diagnostic test #5 and #6 and everything is fine. The mpu has the piggyback with 93 chips at u3 & u4 and 90 chips at u18 & u20. I clear the ram by installing a jumper at j14 and turn it on while holding the pseudo coin button on the door distro board until I get the CH followed by CL then power down remove jumper and power up that's what I have to do each time after I run into the problem. I am not sure if I am doing this correct and any help is appreciated. I am new to slots but I enjoy tinkering with electronics.

[CVslots]

So what is the error 51? Have you searched that?

[coffinails74]

Yes  I believe that is door unlocked but I haven't had any luck finding info about the 3.3. 1 Thank you for the quick reply. I have replaced the battery and I noticed another area for a battery on the backplane board. I am not sure if it is supposed to have one but it currently doesn't.