• Supported Platforms
• M120 Routers

• Related Topics
• M120 DC Power Supply Description
• Electrical Specifications for the M120 DC Power Supply
• Maintaining the M120 Power Supplies
• Installing an M120 DC Power Supply

Removing an M120 DC Power Supply

The power supplies are located at the rear of the chassis to the right of the CB1. Each power supply weighs approximately 8.4 lb (3.8 kg).

Caution: Do not leave a power supply slot empty for more than 30 minutes while the router is operational. For proper airflow, the power supply must remain in the chassis, or a blank panel must be used in an empty slot.

Note: After powering off a power supply, wait at least 60 seconds before turning it back on.

To remove a DC power supply:

1. Make sure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cables might become active during the removal process.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
3. Switch the circuit breaker on the power supply faceplate to the off position (O).
4. Remove the clear plastic cover protecting the terminal studs on the faceplate.
5. Remove the nut and washer from the terminal studs (see Figure 1). (Use a 3/8-in. nut driver or pliers.)

   Figure 1: Disconnecting Power Cables from the M120 DC Power Supply

   

6. Remove the cable lugs from the terminal studs.
7. Loosen the captive screws on the cable restraints on the lower edge of the power supply faceplate.
8. Carefully move the power cables out of the way.
9. Loosen the captive screw on each flange at the top and bottom of the power supply faceplate completely.
10. Grasp the handle on the power supply and pull firmly. Slide it halfway out of the chassis (see Figure 2).

    Warning: Do not touch the power connectors on the rear of the power supply (see Rear of the Power Supply Showing Midplane Connector). They can contain dangerous voltages.

11. Place one hand underneath the power supply to support it and slide it completely out of the chassis.

    Caution: Each power supply weighs approximately 8.4 lb (3.8 kg). Be prepared to support the full weight of the power supply as you remove it from the router.