Editing Apple II General Maintenance (section)

== Safety Precautions ==

Working on Apple II computers requires careful attention to electrical safety and component protection from static discharge. The computer's age makes components particularly vulnerable to damage from improper handling.

=== Electrical Safety ===
Before performing any maintenance:
* '''Always disconnect power''' from the computer and wait at least 30 minutes for capacitors to discharge
* '''Remove all peripheral cards''' from expansion slots before working on the motherboard
* '''Disconnect the keyboard cable''' at the motherboard connector to prevent accidental shorts
* '''Never work on power supplies''' with the unit plugged in - even when switched off, lethal voltages remain present

The power supply contains high voltage components that retain charge after disconnection. The main filter capacitor (typically 2200µF) can hold dangerous voltage levels for extended periods. If power supply work is necessary, discharge capacitors safely using a 10kΩ resistor across the terminals, never with a screwdriver or metal object which can cause component damage.

=== Static Protection ===
The MOS technology chips used in Apple II computers are extremely sensitive to electrostatic discharge. Components from the 1970s and 1980s are particularly vulnerable, with damage occurring from as little as 10 volts of static electricity - well below the 1500 volt threshold humans can perceive.

Essential static precautions include:
* '''Use an anti-static mat''' when working on circuit boards, connecting it to a proper ground point
* '''Wear an anti-static wrist strap''' connected to ground through a 1MΩ resistor for safety
* '''Store chips in anti-static foam''' or conductive bags when removed from sockets
* '''Handle chips by their edges only''', never touching the pins directly
* '''Work in 70-90% humidity''' when possible to reduce static buildup
* '''Avoid wearing polyester clothing''' or working near plastic materials

When anti-static equipment is unavailable, touch both hands to a grounded metal surface before handling chips. Aluminum foil or anti-static bags from electronic components can serve as temporary work surfaces, but never power the computer while on these conductive materials.