If the fuse is blown, they should be looking for the cause. The new one
may blow right away, or some time later.

A blow fuse in any of these electronic devices, is usually caused by
something else that is failing.

I know that during the warranty, you may have to pay the transport.
But, if the set is under warranty, why are you calling an independent
shop? If they work on the set, the factory warranty will be void.