Editing Apple Trackball (section)

== Repair Procedures ==

=== Cable Repair ===

ADB trackballs typically had permanently attached cables prone to failure at the strain relief.

'''Testing cable integrity:'''
# Use multimeter in continuity mode
# Check each conductor (4 wires: +5V, Ground, Data, PSW)
# Flex cable while testing to find intermittent breaks
# Common failure point: 2-3 inches from device

'''Repair method:'''
# Disassemble trackball completely
# Cut cable past break point
# Strip and tin wire ends
# Solder to PCB maintaining color code:
## Red: +5V
## Black: Ground
## Green: Data
## Yellow: Power switch (if present)

# Add heat shrink for strain relief
# Consider adding flexible silicone at exit point

=== Switch Replacement ===

'''Identifying switch type:'''
* Most use Omron D2F series microswitches
* Some use Alps SKHHAJ series
* Measure physical dimensions before ordering

'''Replacement procedure:'''
# Desolder defective switch with desoldering braid
# Note orientation of switch terminals
# Install new switch ensuring flat mounting
# Test actuation before reassembly
# Adjust actuator arm if necessary

=== Bearing Replacement ===

'''Ruby/Ceramic bearings (Kensington):'''
* '''Part identification:''' Usually 3mm ceramic balls
* '''Source:''' Industrial bearing suppliers (Si3N4 ceramic)
* '''Installation:''' Glue with cyanoacrylate adhesive
* '''Alignment:''' Critical for smooth operation

'''Roller replacement (Mechanical):'''
* Clean shaft thoroughly
* Check spring tension
* Ensure perpendicular alignment
* Test free rotation before assembly

=== Optical Sensor Cleaning ===

'''For optical trackballs:'''
# Locate sensor windows (usually 2-4)
# Clean with cotton swab and isopropyl alcohol
# Check for scratches on windows
# Verify LED illumination with digital camera
# Clean ball pattern if applicable