Feature LED Color/Display Comment
DIAG LED
• Off –— Normal operating
• Solid green –— System
Booting or Diagnostics
PSU side
FAN LED
• Solid green –— Fan powered
and running at the expected
rpm
• Solid red –— Fan failed
PSU side
STACK LED
• Solid blue –— Switch in
stacking master mode
• Solid green –— Switch in
stacking slave mode
• Off –— Switch in stand-alone
mode
PSU side
LOCATOR LED
• Blinking blue –— Locator
function is enabled
• Solid blue –— Locator
function is disabled
PSU side
NOTE: The system temperature threshold is 75°C. When one of the thermal sensors exceeds this
temperature, the TEMP LED turns RED.
Table 3. 10GBT Ethernet Port LEDs
Feature LED Color/Display
Link LED
• Off –— No Link
• Solid green –— Link on 10Gbps speed
• Solid Amber –— Link on 100M or 1Gbps speeds
Activity LED
• Off –— No Link
• Blinking green –— Transmit/Receive is active
Table 4. QSFP+ Port LEDs
Feature LED Color/Display
Link LED
• Off –— No Link
• Solid green –— Link on 40Gbps speed
• Solid amber –— Link on other speeds
Activity LED
• Off –— No Link
• Blinking green –— Transmit/Receive is active
Table 5. OOB Ethernet Port LEDs
Feature LED Color/Display
Link LED
• Off –— No Link
• Solid green –— Link on 1Gbps speed
The S4820T Switch
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