Specifications

Replacing Parts
Cisco MGX 8220 Reference, Release 4.1
8-4
To install a back card:
Step 1 Position the extraction levers so they lie flush with the card’s faceplate.
Step 2 Position the rear card guides over the appropriate slot at the top and bottom of the card cage.
Step 3 Gently slide the card all the way into the slot and tighten the two captive screws on the back
card’s faceplate. Tighten the upper and lower screws alternately to prevent mis-alignment
of the card. Do not overtighten. Tighten the screws to secure the card.
WarningCards must be inserted in the correct slot positions. This is particularly true with back cards. If
service module back cards are inserted into slots intended only for ASC and/or BNM back cards (slots 1, 2,
3, and 4) damage to the card and backplane can result. If you accidentally attempt to insert a service module
back card into slots 1, 2, 3, or 4 and have difficulty in operating the shelf, examine the backplane pins and the
connector on the wrongly inserted back card to see if they have been bent or damaged.
Replacing a DC Power Entry Module
DC Power Entry Modules (PEM) contain few active components so they should rarely need
replacement. Access is from the back of the shelf. To remove a PEM, proceed as follows:
Step 1 Press the red button on the power entry module you need to replace. This removes power
from the module.
Step 2 Disconnect the 48VDC power cable from the module.
Step 3 Pull out the power entry module from its slot.
Step 4 Slide in the replacement module until its connector seats in its socket.
Step 5 Replace the 48VDC power cable.
Step 6 Press the black button on the power entry module until it latches in the IN position.
Replacing the Cooling, Booster, Plenum, and AC Power Assemblies
To replace the assembly:
Step 1 Remove any cables at the rear of the assembly that connect to the shelf or other modules.
Step 2 Remove the screws attaching the assembly to the rack.
Step 3 Pull the assembly out of the rack.
Step 4 Slide the new assembly into the rack.
Step 5 Use the screws to attach the assembly to the rack.
Step 6 Reconnect the cables from the shelf or other modules to the new assembly.
WarningIf you replace the cooling assembly with power applied to the shelf, you must work quickly to
prevent heat buildup in the shelf which could damage the cards.