5-4
EMC Connectrix B Series DS-4900B Version 5.1 Hardware Reference Manual
Power Supply Replacement
Items required
You need the following items to replace a power supply in a 
DS-4900B:
◆ DS-4900B switch
◆ New power supply
◆ Phillips-head screwdriver #1
Replacing a DS-4900B switch power supply
To replace a power supply unit in a DS-4900B: 
1. To leave the switch in service while you replace a power supply, 
verify that the other power supply (the one not being replaced) 
has been powered on for at least four seconds and has a green 
LED.
2. Power off the power supply by pressing the AC power switch to 
the “0” symbol. See Figure 5-1 for the location of the AC power 
switch.
3. Unplug the power cord from the power supply that you are 
replacing.
4. Unscrew the captive screw on the power supply that you are 
replacing using the Phillips-head screwdriver. 
5. Remove the power supply from the chassis by pulling the handle 
on the power supply out, away from the chassis.
6. Install the new power supply in the chassis:
CAUTION
Do not force the installation. If the power supply does not 
slide in easily, ensure that it is correctly oriented before 
continuing.
a. Orient the power supply as shown in Figure 5-2 on page 5-5, 
with the AC power switch on the left.
b. Gently push the power supply into the chassis until it is firmly 
in.