IBM A40I TYPE 2271 User Manual

Page of 148
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:  
1.    
Use product-specific ESD procedures when they exceed the requirements 
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. 
 
 
Keep the parts in protective packages until they are inserted into the product. 
 
 
Avoid contact with other people. 
 
 
Wear a grounded wrist strap against your skin to eliminate static on your body. 
 
 
Prevent the part from touching your clothing. Most clothing is insulative and 
retains a charge even when you are wearing a wrist strap. 
 
 
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.
 
 
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: 
 
 
Electrical hazards, especially primary power (primary voltage on the frame can 
cause serious or fatal electrical shock). 
 
 
Explosive hazards, such as a damaged CRT face or bulging capacitor 
 
 
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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