Pcm Faults; Thermal Monitoring And Control; Thermal Alarm - Seagate 5005 Series Hardware Installation And Maintenance Manual

PCM Faults

Symptom
Ops panel Module Fault LED is amber
Fan Fail LED is illuminated on PCM
1-See Figure 26 (page 34)
2-See Figure 28 (page 36)

Thermal monitoring and control

The storage enclosure system uses extensive thermal monitoring and takes a number of actions to ensure component
temperatures are kept low, and to also minimize acoustic noise. Air flow is from the front to back of the enclosure.
Symptom
If the ambient air is below 25ºC
(77ºF), and the fans are
observed to increase in speed,
then some restriction on airflow
may be causing additional
internal temperature rise.
NOTE: This is not a fault
condition.

Thermal alarm

Symptom
1. Ops panel Module Fault
LED is amber.
2. Fan Fail LED is illuminated
on one or more PCMs.
90 Troubleshooting and problem solving
Cause
1
Any power fault Verify AC mains connections to PCM are live
2
Fan failure
for visual reference of Ops panel LEDs.
for visual reference of PCM LEDs.
Cause
The first stage in the thermal
control process is for the fans to
automatically increase in speed
when a thermal threshold is
reached. This may be caused by
higher ambient temperatures in
the local environment, and may
be perfectly normal.
NOTE: This threshold changes
according to the number of disks
and power supplies fitted.
Cause
Internal temperature exceeds a
preset threshold for the
enclosure.
Recommended action
Replace PCM
Recommended action
1. Check the installation for any airflow
restrictions at either the front or back of the
enclosure. A minimum gap of 25 mm (1") at
the front and 50 mm (2") at the rear is
recommended.
2. Check for restrictions due to dust build-up.
Clean as appropriate.
3. Check for excessive re-circulation of heated
air from rear to front. Use of the enclosure in
a fully enclosed rack is not recommended.
4. Verify that all blank modules are in place.
5. Reduce the ambient temperature.
Recommended action
1. Verify that the local ambient environment
temperature is within the acceptable range.
See also "Environmental requirements"
(page 140).
2. Check the installation for any airflow
restrictions at either the front or back of the
enclosure. A minimum gap of 25 mm (1") at
the front and 50 mm (2") at the rear is
recommended.
3. Check for restrictions due to dust build-up.
Clean as appropriate.
4. Check for excessive re-circulation of heated
air from rear to front. Use of the enclosure in
a fully enclosed rack is not recommended.
5. If possible, shut down the enclosure and
investigate the problem before continuing.