Gefran 800 Controller Error

Hi,

I'm having a serious problem with the GeFran 800 controller. I tried everything to reboot, but it still could not connect to the temperature tuner and did not display the installed temperature

When I run a dangerous error:
- Off-line oven power / safety door open
- Oven communication fault (check power)
- Zone 1 thermoregulator communication fault
- Zone 2 thermoregulator communication fault
- Zone 1 fan 1 communication fault
- Zone 2 fan 1 communication fault
- Zone 2 fan 2 communication fault