Juniper Internet Router M160 Hardware Manual page 241

If the spare power supply also does not work, connect the router to a different
3.
power source. You might also try replacing the power cord or cable. For
instructions, see "Disconnecting and Connecting Power" on page 200 (you do
not need to disconnect and reconnect the grounding cable).
If you cannot determine the cause of the problem or need additional assistance,
4.
see "Juniper Networks Technical Assistance Center" on page 212.
Troubleshooting Hardware Components
Troubleshooting the Power System
217