Lexmark 5021-0XX User Manual

Page of 385
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.