GW instek power supply, PSP series (PSP-405) is not showing the correct current

[matt6ft9]

Some history: 
When the power supply output was turned on, the current would show about 13mA of load, even though nothing was attached.  After some trial and error,  IC 10, a TL072CF (Dual low noise JFET Op-Amp), was found to have a large temperature dependency.  If it was heated, it would show the correct current (0mA) with no load.  If IC10 was hit with freeze spray, it would show about 36mA output current with no load.

Four replacement TL072CF's were ordered.  One was placed into an 8 pin socket on IC10. 


Now, the current is about 100mA too low. 
details:
   -with the 12V output on, the TL072 pin 4 (V--) to pin 7 (2 out)
      output load   PSP-405 display value   pin 7 voltage
      open              0mA                     12.30V
      200mA           100mA                  12.66V
      300mA           200mA                 12.85V
      400mA           300mA                 13.04V
      500mA           400mA                 13.23V
      1A              901mA                 14.18V
      1.5A              1401mA                 15.17V      

My thought right now is the software calibration is off.  The older, 8051 version of the power supply has a calibration procedure.  However, this is the newer MSP430 based version of the power supply and doesn't have trimmer pots used in the calibration. 

Here are some good images of the MSP430 version, posted by another:
https://www.eevblog.com/forum/testgear/gw-instek-psp-603-60v-3-5a-power-supply-(short)-review-and-teardown/msg1313021/#msg1313021

Link to the 8051 version of the calibration
www.gwinstek.com%2Fen-global%2Fproducts%2FdownloadSeriesDownNew%2F7339%2F1426&usg=AOvVaw3FLPeVyejdBa5HbFCyXFfq

So, does anyone know the calibration procedure for the newer style MSP-430 based power supply?  Or, are there any other thoughts on how to repair the current reading offset?

Some links were found to power supplies with current reading issues, but they don't seem to be relevant to this specific issue:
https://www.eevblog.com/forum/repair/agilent-e3633a-e3634a-power-supply-current-calibration-(13ma-offset)/msg3000344/#msg3000344

https://www.eevblog.com/forum/repair/e3631a-power-supply-showing-70ma-with-nothing-connected/msg786592/#msg786592

https://www.eevblog.com/forum/repair/gw-instek-gps-4303-power-supply-ch2-set-always-low/msg1140106/#msg1140106

-Matt