Buzz sound when doorbell depressed... but lost chime. Hard wired Nutone unit. Help. Cleaned contacts on button.

Remove chime cover. Have someone press the door bell button. Does solenoid move and strike the chime bar. Show picture of chime.

Shoot a little WD40 of the plunger and try the bell.

Sorry but I have to disagree Brian. Never lubricate a solenoid, as per manufacture's instructions. Plus WD40 is not a lubricant.