Ensoniq DP4 problem

Hi,

I am looking for the Ensoniq DP4 Schematics. (NOT the DP4+). It seems impossible to find that one online …

Story:
I got an Ensoniq DP4 which needs repair.
All peak lights are on, get a “Bad DC Offset error” message sometimes. It also always give me a low battery warning even tho, the battery is brand new.

I went thru a full refurbish with the Kit you can find on ebay ( https://www.ebay.com/itm/274594614456 )
but the same problem remains.

Also if anyone have experience with this problem please let me know !

Thank you for your help !