Connector & layout: The replacement must match the original in contact pad layout and orientation so the motor sits flush without interfering with other components.

Mounting & stability: Often attached with foam/adhesive to reduce rattling — a loose or mis-mounted motor can cause noise or weak vibration.

Functionality check: After installation you can test via the phone’s diagnostic mode (dial *#0*# on many Samsung devices) to trigger vibration and confirm full operation. > “If it doesn’t work … your vibration motor has likely shaken its booty for the last time.” Reddit+1

Severity of failure: Typical symptoms of a bad motor include no vibration at all, very weak vibration, or unusual buzzing/rattling noise when it should vibrate.

Replacement caution: When replacing, disconnect power/battery, ensure no debris in housing, align motor exactly, replace any removed adhesive/foam. Poor installation can lead to reduced performance, shorting, or interference