Anyone know anything about cable modem connectivity issues?

[petronius]

I have kind of a weird problem in that my cable modem (Charter) loses its connection irregularly, sometimes several times per day, sometimes days in between.

The Charter technicians say the signal is fine to the box outside, but something is causing a loss between the outside box and the modem - IOW, it's my problem, and I have to pay for a wall fish to replace the line in the house.

The odd part though: powering the modem off/on doesn't often fix it, BUT, it invariably reconnect immediately if I power off, briefly disconnect the cable itself from the modem, reconnect the cable, and power on.

Any idea why that would work (it's not something the cable techs suggested)?

[PoliticAverse]

1. Perhaps there's a problem with the cable that connects to the back of the modem.

Does the cable connect to a jack on the wall, or does it come straight out of the wall and
go right to the back of the modem?

[petronius]

2. Cable comes straight from the wall (no jack)

The plate is glued down, and it's not clear exactly how the cable runs from the box to the modem--old house, with a lot of inaccessible space--but it does seem there's an otherwise unused splitter somewhere along the run.

The modem was also replaced, with no effect.

It doesn't seem unlikely that there's a problem with the cable along there, but I'd like to know why unscrewing the cable fixes the problem when (un)powering alone doesn't. (Ideally, I'd like a reason why it's Charter's fault, so they can pay for the line and not me! )

[PoliticAverse]

3. Is it a push-on or screw on connector on the cable end?

If you jiggle the cable in back does the modem lose connection?

[petronius]

4. Screw on - the modem has been moved around without a loss of connection, and

the connection losses occur without any physical disturbance of the modem or cable...

(Just went a gave it a good shaking, and I'm still here!)

[bananas]

6. Sounds like a grounding problem. nt

[JayhawkSD]

5. When you say it loses its connection...

What are you basing that on: flashing cable light on the modem, or loss of Internet access on the computer?

My computer goes offline once in a while and it's because the cable modem lost contact with the Cox signal briefly and when it regained the signal my computer did not restore the network connection with the modem. Shutting down the modem does not fix that, but rebooting (restarting) the computer does.

You can tell if it's the computer network rather than the cable modem by looking at the lights on the cable modem. One of then indicates the status of the cable signal, steady indicating connection and blinking meaning no signal.

The Charter techs should be able to read the signal all the way to your modem, by the way, just as they can to your television box, and I have to wonder why they are not commenting on that. Last time I upgraded my modem it was because the Cox tech said, "I see you have..." and told me my cable modem was a lower speed than the service they were providing.

[ohheckyeah]

7. I had a very similar problem

with my internet connection. I ask my husband to check the inside of the box outside. My problem turned out to be a box full of wasps and a wasp nest about the size of the box.

Weird, but true. Once the nest and wasps were gone it's been fine.

[bananas]

8. The likely problem and solutions explained here

http://www.dslreports.com/forum/r8166973-Madison-Tech-says-Need-voltage-blocker-on-TV

on edit: there could be other problems, like a neutral fault. If you have a clamp-on ammeter, see if there's a current on the coax shield.