Re: Neff H5972N0GB/01 microwave
these units are based on the Panasonic design using an invertor and magnetron. the unit detects if the mag has energised properly and if it does not it will abort the programme. Normally after 10 to 15 secs. it is likely that when the unit aborts it goes into the cool down mode.
with your fault, if the microwave fuse is ok it is likely to be the mag ( but I cant promise ) . look at the magnets to see if one of them is damaged
unfortunately you cannot be certain of the invertor until you put a new mag in
Dave