In the event that a cable modem does not appear to be functioning properly, use the following troubleshooting tips to assist in solving the problem.
Make sure that the RF cable is securely attached to the coaxial port of the cable modem. You may also want to make sure that the other end of the RF cable is securely attached to the coaxial jack provided for the cable modem's location.
Check the status of the LEDs to determine if the cable modem is scanning for the downstream. During the scanning process, the LEDs of the cable modem will appear like this:
Once the downstream has been determined, and the cable modem has established QAM lock, the LEDS will appear like this:
Check the Downstream Status page of the Web diagnostic pages in the cable modem to determine if QAM lock has been achieved.
Upstream ranging will not occur until a downstream signal has been successfully acquired and QAM locked.
Once the upstream has been fully ranged and the cable modem has registered itself, the LEDs will appear like this:
Check the Status page of the Web diagnostic pages in the cable modem to determine if it has properly ranged an upstream channel.
Make sure that the cable modem has properly registered with the CMTS. Refer to the Downstream and Upstream pages earlier in this section for troubleshooting tips.
Verify that the cable modem has properly downloaded the DOCSIS configuration file using the Web Diagnostic Interface. This can be determined by checking the Cable Modem Status page or the Operation Configuration page.
In the event that the Transfer Operational Parameters indicator on the Cable Modem Status page of the Web interface does not indicate "DONE," consider the following:
Use the Web Diagnostic Interface to determine if a DOCSIS configuration file was properly downloaded and processed.