"Bestemor kan ikke slå på datamaskinen."
Translation:Grandma cannot turn on the computer.
The way it's pronounced by the TTS sounds like she's hitting the computer, yes, but it's because of the pitch accent and not because of the stress. "Slå på" in tonelag 1 means "hit", in tonelag 2 it means "turn on".
An even funnier pair of phrasal verbs distinguished by pitch accent is "dra til". In tonelag 1 it means "go to", in tonelag 2 it means "punch".