Juniper Networks M160 manual 205

Replacing Hardware Components

WARNING: You must power off the router before removing or installing a fuse.

1.Attach an electrostatic discharge (ESD) grounding strap to your bare wrist and connect the strap to one of the ESD points on the chassis. Make sure the router is attached to a proper earth ground. For more information about ESD, see “Preventing Electrostatic Discharge Damage” on page 226.

2.Remove the rear lower impeller assembly by loosening the thumbscrew at each corner of the impeller cover and sliding the impeller assembly out of the chassis. For complete instructions, see “Removing the Rear Lower Impeller Assembly” on page 155.

3.Determine which fuse has blown. The amber LED under the fuse lights and the indicator bulb becomes visible through the clear cover on the fuse.

4.Power off the router as described in or “Disconnecting Power from the Router” on page 200.

5.Grasp the blown fuse by the edges and rock it in its slot until it comes loose and disconnects. Rock up and down for a vertically oriented fuse (in the groups labeled J241 through J243 in Figure 106) and side to side for a horizontally oriented fuse (in the group labeled J240). If the cover slips off the fuse, snap the cover back into place and begin again.

NOTE: We recommend you use an insulated fuse removal tool to remove fuses.

6.Remove the appropriate spare fuse from the group of fuses labeled J244 in Figure 106. (The labels shown in the figure do not appear on the actual fuses—the clear cover on every fuse reads BUSS GMT-X—but a table on the midplane below the fuse box displays the same information.) Verify that the spare has the same rating and color coding as the fuse it is replacing, as specified in Table 25. To see the indicator bulb and printed rating, look at the fuse from the side.

7.For a vertically oriented fuse, orient the replacement fuse over the slot so that the text on the fuse cover (BUSS GMT-X) reads from bottom to top. For a horizontally oriented fuse, orient the replacement fuse over the slot so that the text on the fuse cover is upside down.

8.Press the new fuse into the slot.

9.Power on the router as described in “Powering On the Router” on page 119.

10.Verify that the amber LED under the replacement fuse is no longer lit.

Replacing Power System Components 205