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78CHAPTER 6: SWITCH MONITORING AND MAINTENANCE
■The Input LED (green) and Output LED (green) stay ON, but the display power command shows that the PSU is not in position (but the other PSU operates normally). Such a problem is likely caused because of the poor contact between the PSU and the backplane due to a badly seated PSU. In this case, switch off the power supply, loosen the captive screws on the PSU, push the PSU into the chassis a little bit, tighten the captive screws, and switch on the power supply to check that the normal state is resumed.
■The Input LED (green) and Output LED (green) are OFF. In this case, check that the power cords are connected correctly, the power cords are in good condition, and the power switch has been put in the ON position.
■The Fail LED (red) is ON. In this case, check that the correct power voltage is in use (i.e., 90 to 264VAC,
■The Fail LED (red) is ON. In this case, check that the air filter protecting the fan tray is clean. Excessive dust accumulated on the air filter will block the fan tray from free ventilation and even lead to power supply failure.
■If you cannot solve the problem yet after going through the above checking steps, contact 3Com technical support engineers rather than disassembling the PSU yourself.
Troubleshooting Fan The Switch 8800 Family provides two LEDs on the fan tray. You can read them and Tray know if the fan tray is OK.
Table 74 Description of fan tray LEDs
Indicator | State description |
|
|
RUN | Green indicates that the fan tray is normally operating. |
| OFF indicates that the fan tray has failed. |
ALM | Red indicates that the fan tray has failed. |
| OFF indicates that the fan tray is in normal state. |
|
|
n The ALM LED on the fan tray keeps ON for 2 to 3 seconds when the switch is powered on.
If the RUN LED is OFF, check if:
■The fan tray has been well seated.
■All the cables connecting the fan tray and the backplane have been correctly connected and are in good condition.
■The fans are working normally.
■The rotation of the fans has not been blocked.
■The blank filler panels have been inserted into those I/O module slots.
Troubleshooting I/O The Switch 8800 Family provides I/O moduleX LEDs on the fabric for the user to Module observe the state of these I/O modules.