Radion will not turn on, batteries OK and in correctly

Check - Bosch Siemens Neff Presostat , this part tell your machine when to stop filling/empty with watter

Is there any thing coming up on screen

the turntable speed is incorrect
adjust with the speed control setting
many quality turn tables have bar codes around the outside edge and when viewed under a light those bars appear to be stationary when the correct table speed is set
It is a strobe affect in time with the frequency of the light

Mechanic is locked in the trunk tapping to get out.
OK is the tapping when turning the key, if so battery is to low to turn over the engine, many things can cause a dead battery. 1) bad alternator if bad your car is a power wheel and the battery will need a charge every time you drive a long distance. the battery is made to start the car once started the alternator runs the car and charges the battery. Crude alternator test, jump car to start once running pull pos. battery cable if car keeps running alternator is OK DO NOT RECONNECT CABLE, TURN OFF CAR FIRST 2) any equipment left on while car sits drawing power like stereo amps etc. 3) corroded and loose cables on the battery (clean and lube)

check motor brush,2 cap to unscew
with new brush check for spark in motor when running,if you have big spark,rotor have a problem

Sounds like the battery is dead. check for voltage at the battery. even new batteries can be bad right out of the box

Fn+F8

tap starter while key is in start position. (need a helper) if it starts change the starter.

does it click?
if so then youv got abad battery conection
if not cheak the nutral safty switch, and then the starter
then the ignition switch

It's most likely the relay for the magnetron malfunctioning. It'll need professional service.