I have a Fresenius 2008H with 31000 hr on it.
It started alarming BP feedback.

I know the alarm is caused by: for 45 sec, the blood pump has been on, and either: the ART-KNOB value has been less than 2 volts (42 units), with the ART-DELIVERY value differing from ART-KNOB by at least 1 volt (22 units); or, the ART-KNOB value has been at least 1 volts, and the ART-DELIVERY value has been less than 1 volt.

Troubleshooting: New brushes, new speed control POT, recalibrated speed. Switched out LP 341 with a new one. New brushes in dearation and flow pump(not related to troubleshooting the BP problem). Still had feedback alarm.

Solution: I moved the left jumper to pin 1 and 2 Problem fixed. (found in an old post from GTSCSS)

Question: I would like to know why this fixed the feedback alarm?
Dose moving the jumper have any other effects on the operation of the blood pump?
Is this safe to put back on the floor?

Hey mk, If I'm not mistaken, blood pump modules are interchangeable between the E and H models. The only difference being the position of that jumper.