Handling Electrostatic Discharge-Sensitive Devices; Safety Inspection Guide - IBM A40I TYPE 2271 Hardware Maintenance Manual

Handling electrostatic discharge-sensitive devices

Any computer part containing transistors or integrated circuits (ICs) should be
considered sensitive to electrostatic discharge (ESD). ESD damage can occur when
there is a difference in charge between objects. Protect against ESD damage by
equalizing the charge so that the machine, the part, the work mat, and the person
handling the part are all at the same charge.
Notes:
Use product-specific ESD procedures when they exceed the requirements
1.
noted here.
2. Make sure that the ESD protective devices you use have been certified (ISO
9000) as fully effective.
Use the following precautions when handling ESD-sensitive parts.
v Keep the parts in protective packages until they are inserted into the product.
v Avoid contact with other people.
v Wear a grounded wrist strap against your skin to eliminate static on your body.
v Prevent the part from touching your clothing. Most clothing is insulative and
retains a charge even when you are wearing a wrist strap.
v Select a grounding system, such as those listed below, to provide protection that
meets the specific service requirement.
Note: The use of a grounding system is desirable but not required to protect
against ESD damage.
– Attach the ESD ground clip to any frame ground, ground braid, or green-wire
ground.
– Use an ESD common ground or reference point when working on a
double-insulated or battery-operated system. You can use coax or
connector-outside shells on these systems.
– Use the round ground-prong of the ac plug on ac-operated computers.
v Use the black side of a grounded work mat to provide a static-free work surface.
The mat is especially useful when handling ESD-sensitive devices.

Safety inspection guide

The intent of this inspection guide is to assist you in identifying potentially unsafe
conditions on these products. Each machine, as it was designed and built, had
required safety items installed to protect users and service personnel from injury.
This guide addresses only those items. However, good judgment should be used to
identify potential safety hazards due to attachment of non-IBM features or options
not covered by this inspection guide.
If any unsafe conditions are present, you must determine how serious the apparent
hazard could be and whether you can continue without first correcting the
problem.
Consider these conditions and the safety hazards they present:
v Electrical hazards, especially primary power (primary voltage on the frame can
cause serious or fatal electrical shock).
v Explosive hazards, such as a damaged CRT face or bulging capacitor
v Mechanical hazards, such as loose or missing hardware
The guide consists of a series of steps presented in a checklist. Begin the following
checks with the power off, and the power cord disconnected.
1. Check exterior covers for damage (loose, broken, or sharp edges).
2. Power-off the computer. Disconnect the power cord.
Chapter 10. Related Service Information
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