Editing Amstrad CPC 464 Capacitor Replacement Guide (section)

== Safety Warning ==

The CPC 464 '''system unit''' contains no mains voltage and no CRT. Capacitor work on the main PCB and the cassette sub-PCB can be done at the bench with the system unit unplugged from the monitor. Standard anti-static precautions apply.

The CPC 464 '''monitor''' (CTM-640 / CTM-644 colour, GT-64 / GT-65 green) contains a CRT (15&ndash;25 kV anode), mains-rectified bulk capacitors (typically 100 µF/400 V or 220 µF/400 V), and a switching power supply. Before any work that opens the monitor case:

# Power off and unplug the mains lead.
# Wait '''30 minutes minimum''' before opening.
# Discharge the CRT anode through a 1 MΩ / 10 W bleed resistor from the chassis ground to the anode cap, sliding the resistor lead under the rubber boot. '''Do not''' short the anode with a screwdriver &mdash; the inrush can pit the CRT or damage the tools.
# Discharge the PSU bulk capacitor through a 1 kΩ / 5 W resistor.
# Verify both discharges with a multimeter before any work.

Monitor capacitor work is covered in the monitor-specific service manuals (the CPC 464 service manual covers the GT-64 and CTM-640 in pages 18&ndash;30). The detail below covers only the system unit.