Canon FAX-B820, Service Manual

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3.1.2 General Cautions
Damage due to electrostatic discharge
This machine contains contact sensors and printed circuit boards that use ROMs, RAMs, custom chips and other
electronic components that are vulnerable to damage by electrostatic discharge.
Be careful to avoid any damage from electrostatic discharge when conducting service that requires disassembly.
*Static electricity warning
Electrostatic discharge can destroy electronic components and alter electrical characteristics.
Plastic tools and even your hands, if they are not earthed, contain sufficient static electricity to
damage electronic components.
The following materials may be used as countermeasures against electrostatic discharge:
• Earth-connected conductive mat,
• Earth-connected wrist-strap,
• Crocodile clips for the purpose of grounding metallic parts of the main unit.
For service conducted on the user's premises, etc., where such countermeasure materials are not available, the
following countermeasures may be employed.
• Use anti-static bags for the storage and carrying of PCBs and electrical elements.
• Avoid silk and polyester clothing and leather-soled shoes, favoring instead cotton clothes and rubber soled
shoes.
• Avoid working in a carpeted area.
• Before work, touch the grounded earth terminals of the main unit in order to discharge any static electricity.
• Use a wrist-strap and earth the metal parts of the main unit.
• PCBs and electrical elements must be lifted by holding the edges and avoid direct contact with terminals.
*Caution against electrical shock while working with power on
In cases where service must be carried out with power on, via a connected power
cable, be sure to wear an anti-static wrist-strap or other earth, in order to prevent an
electrical path being created through your body.
Attaching and removing cables
Attaching and removing cables with the power still on may cause breakdowns and should be avoided.
In particular, flat cables are likely to cause short circuits. When attaching or removing cables, always
be sure to turn the power off.
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