IBM i 830 Repair Manual page 32

Intermittent Problems
10. All cables that leave each frame must be fastened to the bottom bar of each
11. Where required, ensure that ferrite cores and their covers are installed on both
12. Ensure that all workstation and communications cables meet IBM
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iSeries Model 830, 840, SB2, and SB3 Problem Analysis, Repair and Parts V5R1
v Humidity: 8% to 80% relative humidity
The best operating conditions are:
v Temperature: 23° C (73° F)
v Humidity: 40% to 60% relative humidity
7. Check the air quality in the computer room:
v Look for dust on top of objects. Dust particles in the air cause poor
electrical connections and may cause DASD failures.
v Smell for unusual odors in the air. Some gases can corrode electrical
connections.
8. Ask the customer if any large vibration (caused by thunder, an earthquake, an
explosion, or road construction) occurred in the area at the time of the failure.
Note: A failure that is caused by vibration is more probable if the AS/400
system is on a raised floor.
9. Ensure that all ground connections are tight. These items reduce the effects of
electrical noise.
Check the ground connections by doing the following:
a. Look in the system installation information for instructions on how to
connect the ground straps to the frame bar and the correct hardware to
use. The hardware is part of the ship group kit.
b. Ensure that a star washer is between the head of the screw and the ground
strap.
c. Hold the ground strap and attempt to turn it counter-clockwise around the
screw.
Does the screw loosen?
No Yes
↓
Tighten the screw more, then repeat this step.
d. Measure the resistance between a conductive place on the frame to
building ground or to earth ground. The resistance must be 1.0 ohm or
less.
frame with a cable tie or clamp.
v Ensure that you pull the cable ties tight enough to fasten the cable to the
frame bar tightly.
A loose cable can be accidentally pulled with enough force to unseat the
logic card in the frame to which the cable is attached. If the system is
powered on, the logic card could be destroyed.
ends of all IPI-3 signal cables (DFCI cables) that leave the frame. The ferrite
core can be installed up to 15 cm (6 inches) from the connector; the
recommended distance is 8.5 cm (3.4 inches).
The ferrite core is part 62X1146. The cover for the ferrite core is part 6495272.
Note: If the IPI-3 signal cables do not leave the frame, ensure that they do not
hang below the bottom of the frame. If they do, tie them up inside the
frame.
specifications:
v All connections are tight.