Resolved/Megoldva Teka HL-870 oven, not heating

Hi, to all !

The oven Teka HL-870 do not enable heating elements.
The display, sensor keys, switches, funs are work.
When i connect the oven to power, the display show me few seconds "Sho on", then flashing 12:00.
I think this is "Demo Mode" for exhibitions.

I have read the instructions for this model, but did not see any information about enable/disable demo mode.

May be anybody have service manual for this oven to resolve this problem ?

RESOLVED!
In case of HL 870 ones, you must restart the oven and, until set the time, press the cooking time sensor and cooking stop sensor for 3-5 seconds. Then you can set the time and run the appliance without any problem.