MB21 Removable Fan Tray (F-MB21X-R)

The F-MB21X-R chassis has a removable fan tray located on the upper portion of the rear panel:

F-MB21X-R Fan Tray LED Indicators and Alarms

The following table summarizes the functions of the F-MB21X-R fan tray LED indicators. It also describes the alarm behaviors when faults occur.

Indicator Color & Description			Configuration
Power LED	Status LED	Audible Alarm
OFF	OFF	OFF	No power to chassis.
Solid Green	Solid Green	OFF	Power applied to chassis and no issue/fault is reported.
Solid Green	Solid Red	ON	Chassis Power-ON – Fault(s) Detected. The following faults will trigger the audible alarm and turn the Status LED to RED: One, some, or all fans are blocked, One, some, or all fans have no power, An electrical short is detected (V+ to GND) on the fan tray, Thermocouple is missing, Thermocouple is shorted, Ambient temperature is over 55°C.
Solid Green	Solid Red	OFF	Chassis Power-ON – Fault(s) Detected – Mute button (Alarm ON/OFF) pushed. To mute the audible alarm, push the Alarm ON/OFF button. Once the button is pushed, the alarm is muted. To re-activate the alarm, push the Alarm ON/OFF button a second time.

Topics Discussed

Replacing the F-MB21X-R Chassis Fan Tray