Hi @rami97012
Is there an error code being displayed on the control panel, when the problem occurs?
According to the [document|35695|technical service guide] for your model, there is no ''oven thermal switch'' used in the 30" oven models, only in the 27" models but there is a ''lock thermal switch'' used which may be the cause of the problem - see p.35, although if it is the problem there should be an F9 error code being displayed.
On p.38 there's a schematic diagram for your model that may also help.