Figure 244: M40E M160 Router Fuses - Juniper M Series Monitoring And Troubleshooting Manual

M Series and T Series Routers Monitoring and Troubleshooting Guide
Verify SFM Failure
Check the SFM Connection
Purpose
Action
Check the SFM Fuses
Purpose
Action
450
To verify SFM failure:
Check the SFM Connection on page 450
1.
Check the SFM Fuses on page 450
2.
Perform an SFM Swap Test on page 451
3.
To verify SFM failure by checking the SFM connection.
To check the SFM connection, make sure that it is properly seated in the midplane. Check
the thumbscrews on the ejector locking tabs.
To check for blown SFM fuses.
The M40e and M160 router fuses are located in a fuse box at the rear of the midplane,
behind the lower rear impeller assembly. You must remove the lower impeller assembly
to access the fuses, as described in the M40e Router Hardware Guide.
When the fuse for an SFM blows, the SFM stops functioning even though it is installed
correctly and the power supplies are providing power to the router.
For the M40e and M160 routers, when a fuse has blown but the power supplies are still
delivering power to router, the amber LED adjacent to the fuse lights. See
page 450.

Figure 244: M40e M160 Router Fuses

Another indication that a fuse has blown is that the colored indicator bulb inside it
becomes visible through the clear cover on the fuse. For information about the indicator
bulb color for each fuse type, see the appropriate router hardware guide.
A blown fuse can cause a component to fail even though it is correctly installed and the
power supplies are functioning. Check for a blown fuse in the following circumstances:
The LED that indicates normal operation for the component fails to light.
The appropriate CLI
show chassis environment
is installed but is not receiving power.
Figure 244 on
command indicates that the component
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