IBM 7383, Installation And Service Manual, Page: 11 / 488

Guidelines for trained service technicians
This section contains information for trained service technicians.
Inspecting for unsafe conditions
Use this information to help you identify potential unsafe conditions in an IBM
®
product that you are working on.
Each IBM product, as it was designed and manufactured, has required safety items
to protect users and service technicians from injury. The information in this section
addresses only those items. Use good judgment to identify potential unsafe
conditions that might be caused by non-IBM alterations or attachment of non-IBM
features or optional devices that are not addressed in this section. If you identify
an unsafe condition, you must determine how serious the hazard is and whether
you must correct the problem before you work on the product.
Consider the following conditions and the safety hazards that 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 a bulging capacitor.
v
Mechanical hazards, such as loose or missing hardware.
To inspect the product for potential unsafe conditions, complete the following
steps:
1.
Make sure that the power is off and the power cords are disconnected.
2. Make sure that the exterior cover is not damaged, loose, or broken, and observe
any sharp edges.
3. Check the power cords:
v
Make sure that the third-wire ground connector is in good condition. Use a
meter to measure third-wire ground continuity for 0.1 ohm or less between
the external ground pin and the frame ground.
v
Make sure that the power cords are the correct type.
v Make sure that the insulation is not frayed or worn.
4. Remove the cover.
5.
Check for any obvious non-IBM alterations. Use good judgment as to the safety
of any non-IBM alterations.
6. Check inside the system for any obvious unsafe conditions, such as metal
filings, contamination, water or other liquid, or signs of fire or smoke damage.
7. Check for worn, frayed, or pinched cables.
8. Make sure that the power-supply cover fasteners (screws or rivets) have not
been removed or tampered with.
Safety
ix