1-59
Cisco ONS 15454 DWDM Troubleshooting Guide, R7.0.1
 78-17742-02
Chapter 1 General Troubleshooting
1.10  Power Supply Problems
Warning
Only trained and qualified personnel should be allowed to install, replace, or service this equipment. 
Statement 1030
Warning
During this procedure, wear grounding wrist straps to avoid ESD damage to the card. Do not directly 
touch the backplane with your hand or any metal tool, or you could shock yourself. 
Statement 94
 
Caution Operations that interrupt power supply or short the power connections to the ONS 15454 are 
service-affecting.
Isolate the Cause of Power Supply Problems
Step 1 If a single ONS 15454 show signs of fluctuating power or power loss:
a. Verify that the –48 VDC #8 power terminals are properly connected to a fuse panel. These power 
terminals are located on the lower section of the backplane EIA under the clear plastic cover.
b. Verify that the power cable is #10 AWG and in good condition.
c. Verify that the power cable connections are properly crimped. Stranded #10 AWG does not always 
crimp properly with Staycon type connectors.
d. Verify that 20-A fuses are used in the fuse panel.
e. Verify that the fuses are not blown.
f. Verify that a rack-ground cable attaches to the frame-ground terminal (FGND) on the right side of 
the ONS 15454 EIA. Connect this cable to the ground terminal according to local site practice. 
g. Verify that the DC power source has enough capacity to carry the power load.
h. If the DC power source is battery-based:
• Check that the output power is high enough. Power requirements range from –40.5 VDC to 
–57 VDC.
• Check the age of the batteries. Battery performance decreases with age.
• Check for opens and shorts in batteries, which might affect power output.
• If brownouts occur, the power load and fuses might be too high for the battery plant.
Step 2 If multiple pieces of site equipment show signs of fluctuating power or power loss:
a. Check the uninterruptible power supply (UPS) or rectifiers that supply the equipment. Refer to the 
UPS manufacturer’s documentation for specific instructions.
b. Check for excessive power drains caused by other equipment, such as generators.
c. Check for excessive power demand on backup power systems or batteries when alternate power 
sources are used.