The F1 error code in most of the Kenmore 790 models means the control is not sensing the temperature properly. The tech sheet advises us to disconnect power for 30 to 60 seconds, and after power is reapplied if F1 is still present, replace the EOC (Electronic Oven Control). I suggest after you have disconnected the power supply, if the F1 error comes back you should ohm the RTD sensor (remote temperature detector). If you have a volt/ohm meter and are comfortable working around live electricity I can give you a few checks that will help you diagnose the problem. You did not give me the complete model number, so I have included a set of illustrated instructions for a model I think may be similar to yours. (See images below) I intend for this to be a rough guide only. The pictures may not look exactly like your unit. If your unit has a back cover, it will need to be removed to access the EOC and RTD. Ohm the RTD down the wires with it disconnected at the EOC. At room temperature (approximately 75 degrees Fahrenheit) the RTD should read approximately 1090 ohms. If the RTD ohms in this range and you are sure the connection at the EOC was good, replace the EOC. If the reading is not close to 1091, take the same reading at the RTD. If you read 1091 ohms the wiring harness is bad. If the reading is not close to 1091, the RTD is bad and will need to be replaced.
Without the complete model number, I am unable to help you with part numbers. I did include a link for parts purchases, find your model number and input that number in the space provided. Here is the link
Sears Parts Direct
If you require further assistance please resubmit your question with a
complete model number
and more details. I will be looking forward to helping you again in the near future.