I downloaded all the tech sheets and manuals and read through them for an hour last night. I also checked all previous posts related to drain problems.
The top drawer does not drain properly. I checked the rubber outlet at the air gap and it was clean. When turning the unit on it goes to pump out, and I can hear the water in the sink coming out, which happens twice, and then nothing. The drawer remains full of water (a few inches).
I compared the operation of the top drawer to the bottom and there is a noticeable difference in sound when the pump/wash motor is energized. The bottom drawer sounds stronger and more forceful. My guess is the top drawer is used more often and the drive motor may be worn out, or there is a problem with the control board.
I've not worked on more than five of these in the past 10 years and am not familiar with them in detail. I tried to get the top drawer to go into diagnostic mode several times but it just sits there and does nothing. I tried it all three ways according to the manual and nothing.
What is the hall effect part for? I checked its position and the all the connections and everything seems to be in the correct place.
Can someone out there offer me some direction on this? Thanks!