Diagnostic
Bench time to find out what is actually wrong, and a written quote before any repair work starts.
Nothing gets repaired before it is understood. The diagnostic fee covers the bench time to reproduce the fault, trace it, and tell you what fixing it will cost — in writing, before anything else happens.
If you go ahead with the repair, this comes off the final bill. If the device turns out not to be worth repairing, you are told that plainly and this is all you pay.