Ensoniq DP4 problem

Synth Repair
1

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 !

2

sorry to hear that i wouldn’t buy from those guys when syntaur has everything in respect to parts. look up this issue on you tube guys like bradthx to repair you rack system i’m thinking the capacitors as suspect. good luck

3

The DP4 schematics turned up about 3-years ago

There is a PAL on the DP4 that can be a problem

4

hi @ynv did you have any joy fixing this / locating the issue?

I have the exact same problem!

5

for battery faults change or check battery monitor chip. But usually its bad soldering, check lines to battery monitor IC.

for DC offset you need a scope. You need to analyze s/h circuit for clipping.