For a list of the FRU replacements, see “Accessory and Replacement Parts”.
NVIDIA systems that are equipped with two replaceable power supply units work in a redundant configuration. Either unit may be extracted without bringing down the system.
Make sure that the power supply unit that you are NOT replacing is showing green for the power supply unit LED.
Power supply units have directional air flows similar to the fan module. The fan module airflow must coincide with the airflow of all of the power supply units. If the power supply unit airflow direction is different from the fan module airflow direction, the system’s internal temperature will be affected. For power supply unit air flow direction, refer to Air Flow.
To extract a power supply unit:
When replacing a faulty fan unit in an operational switch system, do not leave the slot unpopulated for more than 60 seconds.
Remove the power cord from the power supply unit.
Grasping the handle with your hand, push the latch release with your thumb while pulling the handle outward. As the power supply unit unseats, the power supply unit status LEDs will turn off.
Remove the power supply unit.
PS Unit Pulled Out 
*Illustration only. The design may vary in different systems.
To insert a power supply unit:
Make sure the mating connector of the new unit is free of any dirt and/or obstacles.
ImportantDo not attempt to insert a power supply unit with a power cord connected to it.
Insert the power supply unit by sliding it into the opening, until a slight resistance is felt.
Continue pressing the power supply unit until it seats completely. The latch will snap into place, confirming the proper installation.
Insert the power cord into the supply connector.
Insert the other end of the power cord into an outlet of the correct voltage.
ImportantThe green power supply unit indicator should light. If it does not, repeat the whole procedure to extract the power supply unit and re-insert it.
The system can fully operate if one fan FRU is dysfunctional. Failure of more than one fan is not supported.
Make sure that the fans have the air flow that matches the model number. An air flow opposite to the system design will cause the system to operate at a higher (less than optimal) temperature. For power supply unit air flow direction, refer to Air Flow.
If operating the systems at full capacity with all ports occupied, and at 40°C ambient temperature, and one of the system fans becomes faulty, it is recommended to replace the fan within 24 hours of failure.
To remove a fan unit:
Grasping the handle with your right hand, push the latch release with your thumb while pulling the handle outward. As the fan unit unseats, the fan unit status LEDs will turn off.
Remove the fan unit.
SN3700/SN3700C Fan Module Latches
SN3750-SX Fan Module Latches
SN3420 Fan Module Latches 
To insert a fan unit:
Make sure the mating connector of the new unit is free of any dirt and/or obstacles.
Insert the fan unit by sliding it into the opening until slight resistance is felt. Continue pressing the fan unit until it seats completely.
ImportantThe green Fan Status LED should light. If not, extract the fan unit and reinsert it. After two unsuccessful attempts to install the fan unit, power off the system before attempting any system debug.