As I've been taught that complements within the sentences follow a specific order ( time, cause, way, place), I'm wondering if the object (Computer) goes before or after the time expression.Both versions are correct - but include a small mistake.
Both sequences are correct. But "reparieren" requires akkussative cae: "meinen Computer".
Der Techniker wird nächste Woche meinen Computer reparieren. - The Focus is at "computer". (example: The computer, and not the TV)
Der Techniker wird meinen Computer nächste Woche reparieren. - The Focus is at the time: (next week, not in a month)
So what exactly do you mean?