5-2 CHAPTER 5: PROBLEM SOLVING
DUA1800-0AAA04

Spares

The LinkBuilder MSH has been de signed to provide resilience and
reliability. It is good practice that you hold spares. We recommend
that you have 1 spare module or power supply unit for every 10 in
use. In the unlikely event that you have problems with the MSH,
you should swap the faulty module, thermal management unit or
power supply unit with a spare.
In addition to the above, it is advisable to carry spare replaceable
components, such as fuses. A list of recommended component
spares, if any, is given in the corresponding module or
Management Module User Guide.
Spot Checks
We recommend that you check the MSH visually at frequent
intervals. Regular checks can give you an early warning of a
possible failure.
Check the following:
All LEDs. Press the Lamps button located on the display panel.
Check that all LEDs light. If they do not, an LED has probably
failed.
POWER FAIL LEDs. Check that, during normal operation, these
LEDs are not lit.
Fans. If a fan in the thermal management unit (TMU) has failed
the FAIL LED on the display panel of the MSH will light up.
Cabling. Check that all external cabling connections are secure
and that no cables are pulled taut. Also check that any AUI cables
used are secured using the slide locks fi tted.
Modules. Check that all modules are secured in position and
flush with each other.

Chassis.bk : CHAPTER5 Page 2 Monday, February 10, 1997 1:11 PM