Please Help With EPC-7 (Patch Clamp Amplifier)

[Zakaria Mtchedlishvili]

Hello Folks,

I have an List EPC-7 (same as Heka),which  Iam trying to put in business but
I have a problem: The pipette offset current does not zero when I immerse
pipette into the bath. That is, the offset potentiometer range is not
enough. I can zero it only by adjusting command potential (approx 15 mV,  I
have near symmetrical Cl). We have shipped the unit to Heka service center
in Canada and it was supposidingly fixed, but the problem remains just as it
was before!
Has anyone encountered similar problem with EPC-7? I need to set up another
rig and hate to spend 10K on a new Axon when there is an amplifier sitting
on the shelf. I've heard that it can produce very low noise recordings.

-Thanks in advance for your help.

Zaza Mtchedlishvili