[PakG1]

What hardware repair would require handing over your passcode? If it's to test that the phone is working fine after the repair, can't you test it yourself in front of them before you pay? If they were doing software repairs, what would be the nature of the repair? Hard for me to imagine anything to repair software-wise, given how iOS is.

[stirlo]

Anything that requires turning off the phone will need a passcode once it powers on. This includes battery replacement, screen, microphone, camera, etc. Only for camera repairs is it feasible to test fully without entering a passcode. Of course you could leave the testing until you pick it up and pay but then if something is faulty you’ll have to come back later and wait longer when they might have been able to repair beforehand if they’d known.

[PakG1]

Having watched full screen replacements, button replacements, and battery replacements on my iPhone, I suppose I don't understand why one wouldn't just wait the extra 5 minutes to get the issue resolved. Repairs can get done really fast in my experience.