Top shelf won't clean.
Cleaned chopper assy and flapper valve. All arms and roof spinner and water tubing were clear of debris. Marked upper arm and roof spinner to see if they moved during run cycle. The only thing that moved was the lower arm.

Suspect pump issue. Can it be checked without removal.

Any other possible causes?

How high should the water be?
How do you determine when the fill cycle occurs and when it is complete?

[COLOR="Blue"]How high should the water be?[/COLOR]
Most units fill to just under the heater.
[COLOR="Blue"]
How do you determine when the fill cycle occurs and when it is complete?[/COLOR]
You should be able to hear it.

[COLOR="Blue"]I assume the fill valve is the first electrical component that the water flows through from the supply line.?.?[/COLOR]
Yes

OK denman... I don't know what happened, but....... I emptied the DW and took out the racks. I attached a rubber glove over the outlet for the middle spray arm to see if it was providing water and how much. I indexed the bottom arm and the top ceiling spinner. I ran a heavy/high temp wash. To my surprise both the lower spray arm and the top spinner had moved. The rubber glove was full of water. The second time I ran the same test the rubber glove was ripped. I then put the racks back in, placed a cutting board on the top rack to block the water from the middle arm and then placed four cups on top of the cutting board to see how much water came from the ceiling spinner. After indexing all three arm/spinners I again ran a heavy/high temp wash. All three sprayers had moved and all four cups were full to the brim with water. So..... All "seems" to be working. Go figure! I'm holding my breath as I suspect this is only temporary.