He said I can bring it in and pay him $100 to get the same answer, he was quite helpful and gave some ideas over the phone to double check.
Had that with our home freezer a while back.
Suddenly started making a terrible noise, so rang a fridge bloke.
He said that'll it be the little plastic bracket that supports the fan will have broken. You can either have a look yourself, or I'll charge you $200 to come out & say the same thing, then another $100 to fix it.
Had a look & yep, the bracket was broken so the fan blades were knocking against the grill. Put a screw in "there" & Bob's your uncle, all fixed & no more noise!
He's doing himself out of easy money, but it's nice to see somebody who cares enough to give his customers an easy, cheap, option!