Hi there,
This brings back memories to when I repaired a cds slot machine.
Awhile back, I worked on a CDS razzle dazzle slot machine that had a system error. After tons of digging around, I found that the issue was that the internal battery died/ or even quickly loses connection. If this happens, it corrupts the entire machine. I have a hunch that this happened to your machines. CDS had chips that reprogram the slot machine. I kid you not, they call them "rebirthing chips". I found a guy online that was able to burn the chips for me. If you would like, I can PM you his contact information. There's a chance that he may have copies of the manuals, and/ or a means of obtaining these chips.
EDIT: I accidentally looked past the ram clear comment as well. I am pretty sure those models need rebirthing chips to clear large jackpots as well.