A failure to synchronize is most frequently a physical problem. No settings on your computer or SOHO router would cause a no-sync situation, and it is very rare to encounter a modem whose configuration is set so as to cause this. Physical problems can take the form of damaged wiring, large amounts of electromagnetic noise on the line, or faulty equipment.
To rapidly troubleshoot a no-sync problem it helps to use process of elimination, cutting out potential issues by bypassing them where possible. During initial troubleshooting the physical problem could be nearly anything, so narrowing down the possibilities is a great first step.
First turn the modem off for about ten seconds, then turn it back on. This is a shot in the dark, but works more often than you may suspect.
Having tried that, ensure that the modem is properly plugged in. Ideally it should run directly to a wall jack carrying your Fusion circuit with as few splitters or couplings as possible. Ensure that the line is connected to Sonic.net Fusion Broadband by plugging a regular corded phone (you should have one of these as you live in California and we get earthquakes) and check for dial tone.
If there is no voice service here, this is a strong indication that the modem is not at fault and that there is a wiring issue. Try again with the corded phone at your phone box. Most single-unit residences have a grey plastic box mounted on the exterior where phone service enters the building. A reasonably-modern phone box will have test jacks specifically for this purpose; just open the box and plug the phone into each jack until you get dial tone. You can make sure the dial tone is provided by Sonic.net by dialing '933' for an emergency 911 location read-back.
If there is no voice service at the phone box, it is possible there is another box on your building. Failing that, you really need to get in touch with Sonic.net
. Inform us of what you observed and we will get the appropriate technicians dispatched to fix you back up.
If there is voice service at the phone box but not at the jack your modem uses, you may need to re-terminate the wiring that runs to that jack. We can send a technician to do this, but fees may apply.
If there is voice service at the jack but no sync, some interference may be introduced by other devices on the line, or by damaged or improperly-installed wiring inside the premises. The most efficient way to eliminate this possibility is to take your modem out to the phone box and try again there. For most phone boxes, the internal wiring for your building is disconnected whenever you use the test jack, so any interference from those sources would be removed from the picture.
If the problem is with the outside wiring or you cannot test at the phone box, there is not a lot of additional troubleshooting to be done for a no-sync issue.
If your modem achieves sync at the phone box, you have an internal wiring issue. Internal wiring can include other devices on the line such as phones, answering machines, fax machines, credit card terminals, DVRs, alarm systems, or anything else that connects to the phone line. Any such devices should have a microfilter attached; typically a modem will come with three to six of these in the box. Unplug every device other than the modem. If the problem persists, the problem is probably the wiring inside the building. Sonic.net may be able to remedy this by running new line to where you keep your modem and filtering off the rest of your wiring.
If your modem cannot sync at the phone box either, the problem is either with the outside wiring or the modem itself. Trying an alternate device would tend to eliminate the modem as the cause of the problem or confirm it.
For intermittent no-sync problems, all of the above is relevant, but most especially while the problem is happening. An important factor in troubleshooting an intermittent problem, where it works sometimes but not others, is when the problems happen, how often, and how long it lasts. If there is any electrical device in the building that is always in use when the problem is happening it may be a contributing factor.