Working on a Samsung DW80M9960US dishwasher.

[hamhock75]

I picked up a non-working Samsung DW80M9960US dishwasher off Craigslist in September for $20 to learn how modern dishwashers work. My last dishwasher was a Bosch Evolution 800 series which is still working fine at over 20 years of age.

The Samsung had been given to the person selling it on Craigslist who gave up working on it. I was told that the waterwall motor was no good. Unfortunately, to get to the motor the prior owner broke one of the waterwall spray arms, lost all the screws holding the waterwall arms and the distributor/waterwall motor assembly, lost the microswitch and screw to the distributor motor.

I have the hardware, broken parts, and microswitch on order.

The Samsung turns on. It tries to move the waterwall vane. The vane moves to the rearmost position then stops. It then seems to try to move the vane to rear several more times even though the vane is already at the rear. Then it just goes quiet with no further sounds. The "power" button light, cycle LED, time display, and the LED that is under the door handle stays on.

I do have both the service and operating manuals but waiting for parts

 

[hamhock75]

This photo is of most of the parts for the waterwall spray assembly.

This is a close up showing that a leaking seal allowed water to fall on and enter the motor that drives the waterwall vane. The inside of the motor had been badly corroded.

This is what happens if you grab the nozzle assemblies to try to separate the two parts held together by a tab in the back. The top half with the distributor, the bottom half with the distributor motor and vane motor.

This photo shows the tab in the back. It can be very stubborn so releasing it takes some care since it is plastic.

Not sure how important preserving that tab is because the two parts are held together with four screws at the points shown by the red circles.

This photo shows the locking tab that is in the service manual to release the distributor motor/microswitch assembly.

What is not mentioned in the manual is that there is a second locking tab at the bottom of white plastic part that holds the distributor motor and microswitch that also has to be released.

 

 

[hamhock75]

https://appliantology.org/topic/97715-samsung-dishwasher-model-dw80m9960ug-distributor-cam-adjustment/#comment-545627

The above link started by Robert Hiebert describes in words how a cam driven by the gear motor and the distributor valve need to be aligned.

"The valve has to be indexed to the cam correctly in order for the controller to correctly determine the position of the valve."

The photos below shows the parts being described above.

 

 

 

[hamhock75]

Here is an interesting video. Except for the door latch problem he is having all the problems I am having.

 

[hamhock75]

The leak occurs on the right side as shown below.

To examine why the leak occurs on the right side an experiment was done.

As the front of the waterwall was raised, the left side touches bottom first.

This lifts the right side up with the drive rail as the fulcrum.

 

[hamhock75]

There is a second reason the leak tends to be on the right side.

The distributor sends twice the volume of water to the left side as can be seen in the photo below.

Versus this for the right side.

But the area of the nozzle openings on the left side are 10% less than twice that of the right side resulting in slightly more pressure and volume on the left side vs the right side. Less volume and pressure gives the streams on the right side more time to droop down under the waterwall.

 

 

[hamhock75]

I tried several solutions to prevent the water from going under the waterwall on the right side.

My first effort used a piece of plastic from a 2 liter soda bottle. I secured the plastic to the waterwall with two nylon 4-40 screws. This worked well for awhile but the plastic is a thermoplastic that was susceptible to the high temperature wash. Over about a dozen washes, the plastic developed additional curvature that let water by again.

My second effort was the same but using a piece of stainless 0.004" thick shim stock. It worked well but the stainless formulation of the shim stock resulted in a rust stain.

My last attempt used a left over 1" wide aluminum louver from a mini-blind I had installed years ago. The aluminum did not rust and left no marks on the stainless bottom since aluminum is softer. Below to the left is the stainless shim and the waterwall with the aluminum blade. The blade is at a slight angle to conform to the bottom of the dishwasher.