GE French Door Refrigerator GFE28HSKFSS Has Marginal Cooling

I have a GE GFE28HSKFSS Refrigerator Serial Number ZH525586 that is about 6 years old. My problem is I have set the freezer temperature to -6 degrees and the refrigerator to 34 degrees and the freezer cools to about 1 deg. F and the refrigerator to about 41 deg. I have done some troubleshooting using the refrigerator diagnostic panel.
Shown below are the reading that I recorded for the various troubleshooting test. The test results for the compressor and defrost heater are not shown because I do not know how these troubleshooting test work.

I am really a kind of newbie on doing diagnostic, but I have determined the following:
The condenser coil and fan blades are clean. There is water in the tray under the drain tube. The compressor housing fells warm to touch. Both refrigerator and freezer compart exhaust fans are blowing air. I have unplugged the refrigerator for 50 minutes to reset the main control panel. I have gone to Channel 16 to properly exit the diagnostic operation. All attempts to get the refrigerator and freezer to get maximum cooling have failed. The refrigerator lately has never been below 41 deg. Also the freezer has never been below 0 to 1 deg.
I think the main control circuit board has failed and the unit is in a default mode with minimal cooling. This board replacement cost is around $200 and I am not sure this is my problem.
I am thinking about entering the diagnostic troubleshooting mode and activate the compressor test for a couple of hours to see if the freezer temperature will decrease. (Note, I have a temperature sensor in the freezer compartment so I can view the temperature remotely.)
Does anyone have any suggestions for more troubleshooting ideas?
Thanks