11-14 Cisco BPX 8600 Series Reference
Replacing Parts
Replacing the Temperature Sensing Unit
The temperature sensing unit is located on the ASM card. If the temperature indication using the
dspasm command does not appear to be correct, try a replacement ASM card.
Replacing Card Slot and Fan Fuses on the System Backplane
There is a separate fuse provided on the System Backplane for each card slot. These fuses are
numbered F4 through F18, corresponding to card slots F15 down through F1 (see Figure 11-6).
There are three separate fan fuses provided on the System Backplane. These fuses are numbered F1
through F3, corresponding to Fans 1 through 3 (see Figure 11-6).
Warning For both personnel safety and to prevent equipment damage, power down the BPX switch before
replacing fan fuses F1 through F3, or card slot fuses F4 through F18 on the System Backplane. For continued
protection against risk of fire, replace only with same type and rating of fuse.
Backplane fuses rarely need replacement. Backplane fuses are intended to prevent catastrophic
damage to the backplane in the event of accidental shorting of -48VDC on the backplane to chassis
ground. This type of event could be caused by bent backplane pins, inadvertent contact of conductive
elements (EMI Cans, EMI Gaskets, etc.) to power pins, or (in the case of a fan fuse) a pinched wire
harness.
These fuses are located in sockets on the backplane and are therefore not readily accessible. A
special tool and a special set of instructions are required for fuse replacement. It is recommended
that only factory-trained personnel perform the procedure. Contact Customer Service for further
information.
