Lexmark 5021-0XX - Manual (Page 232)

4-2 Service Manual
5021-0XX
Handling the printed circuit boards with
MOS ICs
The following precautions must be observed when handling circuit
boards with MOS (Metal Oxide Semiconductor) ICs.
During transportation/storage:
• Do not remove new circuit boards from their protective
conductive bags until needed.
•
Do not store or place circuit boards in a location exposed to
direct sunlight.
•
When it becomes necessary to remove a board from its
conductive bag or case, always place it on its conductive mat in
an area as free as possible from static electricity.
• Do not touch pins of the ICs with your bare hands.
During replacement:
• Before you unplug connectors from the circuit boards, be sure
the power cord has been unplugged from the power outlet.
•
When you remove a board from its conductive bag or case, do
not touch the pins of the ICs or the printed pattern. Place it in
position by holding only the edges of the board.
• Before you plug connectors into the board, be sure the power
cord has been unplugged from the power outlet.
During inspection:
•
Avoid checking any IC directly with a multimeter; use
connectors on the board.
•
Never create a closed circuit across IC pins with a metal tool.
• If it is necessary to touch the ICs and other electrical
components on the board, be sure to ground your body.