For the past 2 weeks or so, our Frigidaire refrigerator has been having trouble making ice (ice in the bin was melting and refreezing), and it had also been showing some condensation inside the fresh food cabinet, both of which I thought might be due to a failing door gasket. However, the temperature inside the fresh food compartment seemed fine, and food was staying frozen inside the freezer. Two days ago, it reported dual OP (thermistor open) codes on the freezer/fresh food temperature display. I power-cycled the refrigerator, and this changed to dual SH codes (thermistor shorted).

It seemed unlikely that both thermistors would go bad at exactly the same time. I've removed the freezer thermistor and tested it with a multimeter, and it appeared to be fine. I pulled the board and checked both thermistors at the connector, and they both seemed to be fine there. Is potentially a board issue? Is there anything else I can check?