IBM 3112, Service Manual

Page: 71 / 184

bh1s.bk : bh1srep.doc 55 Thu Apr 20 12:42:16 1995
Repair Information
55
Repair Information
This chapter explains how to make adjustments to the printer and how
to remove defective FRUs.
Handling ESD-Sensitive Parts
Many electronic products use parts that are known to be sensitive to
electrostatic discharge (ESD). To prevent damage to ESD-sensitive
parts, follow the instructions below in addition to all the usual precau-
tions, such as turning off power before removing logic boards:
•
Keep the ESD-sensitive part in its original shipping container
(a special “ESD bag”) until you are ready to install the part
into the machine.
•
Make the least-possible movements with your body to
prevent an increase of static electricity from clothing fibers,
carpets, and furniture.
•
Put the ESD wrist strap on your wrist. Connect the wrist
band to the system ground point. This discharges any static
electricity in your body to the machine.
•
Hold the ESD-sensitive part by its edge connector shroud
(cover); do not touch its pins. If you are removing a
pluggable module, use the correct tool.
•
Do not place the ESD-sensitive part on the machine cover or
on a metal table; if you need to put down the ESD-sensitive
part for any reason, first put it into its special bag.
•
Machine covers and metal tables are electrical grounds.
They increase the risk of damage because they make a
discharge path from your body through the ESD-sensitive
part. (Large metal objects can be discharge paths without
being grounded.)
•
Prevent ESD-sensitive parts from being accidentally
touched by other personnel. Install machine covers when
you are not working on the machine, and do not put
unprotected ESD-sensitive parts on a table.
•
If possible, keep all ESD-sensitive parts in a grounded metal
cabinet (case).
•
Be extra careful in working with ESD-sensitive parts when
cold-weather heating is used because low humidity
increases static electricity.