Motorola A3100 Troubleshooting Manual page 21

• Remove the lower case and have the vibrator exposed, then retest.
• If retest OK after removing the case, reassemble and check if it is
interfered by the case.
• If retest still fail, check if pin1 of J11 is 5V. If not, check if U2 is
working normally.
• Check if there is PWM signal on pin2 of J11. If not, check if U2 is
working normally.
Service Engineeing & Optimization
Level 3 , Rev.1.0
Vibrator Out Of Control