That is for you to say
How much cost a repair?
How much cost a new machine?
How old is the broken machine?
How long might it last after being repaired?
How long might a repair take?
Is there a budget for either expenditure?
Does the institution have a maintenance technician?
The people here cant't answer any of these questions.
I would guess you would do best to buy a new machine
Amazon offer an A3 laminator for £20
Good Luck..., September 2016