Help please!!! stars and bars bally 5000 plus

[smitty]

Hello I am new to this site. But I have followed it as a guest for 2 wks and learned quite a bit. I have a bars and stars bally 5000 plus that I bought for 200$ knowing it had a error code 83 on it . So I tried to pull out the Io board to reset it and did not work. I switched u12 with u15 on mpu board and it must have cleared because a ch and then a cl came up on display. Then display went blank and that is where I am at. Coins just drop through. I have checked power supply and have all the right voltages. The battery has 3.6 volts, fluorescents come on but no lights in any of the display area. If any body could help it would be greatly appreciated. Also would like to buy a keypad and clear chips. I have a little mechanical and electrical knowledge but this is my first experience looking inside a slot machine.It is a 3 quarter 3 reel machine. The reels turn slow when I push psudo and reset button. Most the dates on chips are 1992 and 1993.

[Badbaud]

How did you clear it?