Cisco GSR12/60 - 12012 Router -AnyLAN, SONET/SDH Installation And Configuration Manual page 260

Removing and Replacing a DC-Input Power Supply
Warning
power source circuit breaker and remove the power supply before accessing the terminals.
Step 3
Step 4
Step 5
7-20 Cisco 12012 Gigabit Switch Router Installation and Configuration Guide
Voltages might be present on the DC-input power supply terminals. Turn off the
Note Turning the power supply switch to OFF (O) releases a latch that secures
the power supply in the power supply bay.
Locate and turn off the source DC circuit breaker that services the power supply
you want to remove. As an added precaution, tape the circuit breaker handle in
the off position.
Using a flat-blade screwdriver or a 10-mm nutdriver, turn the captive jackscrew
counterclockwise (eject) on the power supply faceplate to unseat the power
supply from the backplane power connector. Continue turning the jackscrew to
disengage the jackscrew from the power supply bay (approximately 12
revolutions).
Grasp the power supply handle and slide the power supply halfway out of the
bay. (See Figure 7-8.)