Editing Apple Trackball (section)

== Electronic Troubleshooting ==

=== ADB Controller Issues ===

'''Common controller chips:'''
* '''Kensington:''' Custom ASIC or licensed Apple chip
* '''Logitech:''' Proprietary controller
* '''Generic:''' Often 8051-based microcontroller

'''Testing controller:'''
# Check for +5V at chip power pins
# Verify clock signal (usually 1-4 MHz)
# Monitor data line for activity
# Controller replacement usually not feasible

=== Power Supply Problems ===

'''ADB power specifications:'''
* '''Voltage:''' +5V ±5%
* '''Current:''' 100mA maximum per device
* '''Total bus:''' 500mA maximum

'''Diagnostics:'''
# Measure voltage at device
# Check current draw with ammeter
# Test with external powered ADB hub
# Verify host computer PSU stability