Kenmore 106.45429801 cold freezer, warm refrigerator - control board issue

[OldandSlow]

Roughly 10 year old Kenmore Elite side by side.  Water dispenser began freezing about the same time wife complained of milk going bad. Found freezer at -5F and refrigerator at 42F. I have performed a lot of diagnostics, but still chasing the issue.  This is what I have done:

1. All coils cleaned
2. Air flow verified
3. Refrigerator self diagnostic shows no issues
4. Refrigerator thermistor tested with multimeter (within range) but replaced anyway.

A temperature recorder shows the refrigerator running between 40F and 42F for several days, even though it is set at 33 (lowest setting it will go). The temperature graph is pretty consistent without wide temp swings, just running higher than the set point.
Freezer is set at 4F and runs between 0 and 6. Water dispenser is frozen (when cleared it will refreeze within 24 hours)

I'm leaning toward the refrigerator control board, but have no way to test it, so replacing it will be throwing money at a guess.

Any thoughts as to my next steps? Thanks for any input.

[Daniel.A]

Look at the back wall of the freezer. Do you see any ice/frost buildup?

If no, have you verified the evaporator fan is operational?

 

[OldandSlow]

Thanks Dan.  The outside back of the unit is solid (no exterior coils)  When I pulled the inside cover, the coil inside the freezer was partially frosted, but not great deal.  All fans are working. 

[16345Ed]

15 minutes ago, OldandSlow said:

When I pulled the inside cover, the coil inside the freezer was partially frosted, but not great deal. 

Evaporator should have an even coating of frost. Could be sealed system issue. 

[OldandSlow]

On 12/12/2023 at 6:39 PM, 16345Ed said:

Evaporator should have an even coating of frost. Could be sealed system issue. 

New refrigerator?

 

[evaappliance]

It should not be able to achieve -5 in the freezer if it had a system problem , or a defrost problem for that matter.  Look into airflow 

[OldandSlow]

airflow seems OK - control board on order

 

[OldandSlow]

Update:  Still no joy.  I replaced the control board.  For a while it cooled to 0 on Freezer / 37 on refrigerator.  One day later it's back to a warm 42 degree refrigerator.  I can remove the  air damper and the refrigerator will cool down to freezing.  With the damper assembly removed, I can select the diagnostic and watch the damper cycle open and closed.  When reinstalled, I am back to a warm refrigerator.  I believe the damper is not opening when it should.

So, to date the refrigerator thermistor, control board (W10120824), and damper assembly have been replaced.  The coils are as clean as new, and the fans are both working.  Is there anything else that affects the damper position?

Oh, I did remove the freezer cover & the coils were evenly frosted with no ice buildup.  The defrost coil does heat.