How to repair cable modem(TJ715),

After four years I doubt that you still need instructions on how to repair your cable modem. However, if you are having problems with your cable modem, the first thing that I would suggest is to contact your service provider, because they usually can either fix or replace the modem and will do it for free. Of course this might not always be the case and you should definitely ask to make sure that they will not charge you for their services. If you still need help, then you could always research the topic on the Internet or go to your local library or book store and try to find a manual on the subject.