IBM 6643, 2179 manual Handling electrostatic discharge-sensitive devices, Safety inspection guide

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.

vKeep the parts in protective packages until they are inserted into the product.

vAvoid contact with other people.

vWear a grounded wrist strap against your skin to eliminate static on your body.

vPrevent the part from touching your clothing. Most clothing is insulative and retains a charge even when you are wearing a wrist strap.

vSelect 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.

vUse 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:

vElectrical hazards, especially primary power (primary voltage on the frame can cause serious or fatal electrical shock).

vExplosive hazards, such as a damaged CRT face or bulging capacitor

vMechanical 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.

104Hardware Maintenance Manual