Editing Apple II (section)

== Capacitor Replacement ==
{{main|Apple II Capacitor Replacement}}
RIFA metallized-paper safety capacitors in Apple II power supplies deteriorate over time and require immediate replacement to prevent catastrophic failure with smoke. Replace the X2 safety capacitors (typically 0.1µF and 0.47µF at 275VAC) every year or two as preventive maintenance. Use polypropylene film capacitors from brands like KEMET or TDK as replacements - never use new RIFA capacitors as they have the same failure mode. The Panasonic ECQ-U2A104KL fits as a direct substitute with 20mm lead spacing. Also check capacitor C7 (220µF 10V), which sits near a power resistor and frequently fails due to heat - replace with a 105°C, 16V rated capacitor. When replacing capacitors, always disconnect power and discharge the power supply completely before working. Use proper safety equipment and never work on energized circuits.