6000 reels keep spinning and jitter while initializing them

[DanDudeAmiga]

Hello.  I trying to fix my client's Bally 6000 slot machine.  While initializing the reels it would show result's from the last game.  While doing that the reels jitter as they spin slowly and nonstop.  Power supply is excellent except the 24 volt source measures at 20.  I tried buying a "refurbished" power supply only to measure the same voltage at 20 volts with exactly the same results on the reels.  I tried clearing the memory internally and it worked one time.  But the same issue returned after power cycle/closing the door.  Need help here.