Cleaning Fiber Optic Connectors - Cisco ASR 5500 Installation Manual

Cleaning Fiber Optic Connectors

Step 2
The SDHC card resides in a push-push type holder. With your finger tip, push the rear edge of the SDHC card inward
until you hear a click. Release your finger and the card will pop out of the holder. Remove the card and store it safely
aside.
Step 3
On the replacement MIO/UMIO, locate the SDHC card holder and remove the SDHC card. That card contains only a
basic configuration for testing purposes; insert it into the failed card prior to returning the circuit card to Cisco.
Step 4 On the replacement MIO/UMIO, insert the SDHC card removed from the failed MIO/UMIO. With your finger tip, push
the SDHC card inward until you hear a click and release your finger.
This completes the SDHC card swap out procedure.
Cleaning Fiber Optic Connectors
Fiber optic connectors join optical fibers together. They can be damaged by improper cleaning and connection
procedures. Dirty or damaged fiber optic connectors can degrade communication.
In a fiber optic system, light is transmitted through extremely small fiber cores. Because fiber cores are often
62.5 microns or less in diameter, and dust particles range from a tenth of a micron to several microns in
diameter, dust and any other contamination at the end of the fiber core can degrade the performance of the
connector interface where the cores meet. Therefore, the connector must be precisely aligned and the connector
interface must be absolutely free of foreign material.
Connector loss, or insertion loss, is a critical performance characteristic of a fiber optic connector. Return loss
is also an important factor. Return loss specifies the amount of reflected light: the lower the reflection, the
better the connection. The best physical contact connectors have return losses of better than –40 dB, but –20
to –30 dB is more common.
The connection quality depends on two factors: the type of connector and the proper cleaning and connection
techniques. Dirty fiber connectors are a common source of light loss. Keep the connectors clean at all times,
and keep the dust plugs or covers installed when the connectors are not in use.
As a general rule, any time you detect a significant, unexplained loss of light, clean the connectors. To clean
the optical connectors, obtain and use a fiber optic cleaning kit and follow the manufacturer's usage instructions.
Clean the ferrule, the protective tube or cone that surrounds the fiber core, and the end-face surface of the
fiber core.
If a cleaning kit is not available, follow these steps:
1 Use a lint-free tissue soaked in 99 percent pure isopropyl alcohol and gently wipe the end-face of the fiber
core. Wait for five seconds for the surfaces to dry and wipe the surfaces a second time.
2 Use clean, dry, oil-free compressed air to remove any residual dust from the connector.
3 Use a magnifying glass or inspection microscope to inspect the ferrule at angle. Do not look directly into
the aperture. If you detect any contamination, repeat Steps 1 and 2.
Because invisible laser radiation may be emitted from the aperture of the port when no cable is connected,
Caution
avoid exposure to laser radiation and do not stare into open apertures.
ASR 5500 Installation Guide
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Replaceable Components