Hello,

I moved into a new home about 2 months ago and have had a constant battle with the network since. ISP has been pretty responsive but ultimately not helpful, with 6 techs coming out and not actually fixing anything. The last tech came out and said there was 30 volts flowing through the outer channel in the coax cable from inside the house, and that an un-grounded outlet is likely the reason for my issues. My modem is the only device receiving the coax within the house and it is plugged into a surge protector, which is plugged into a grounded outlet so I don't see how the coax is getting the additional voltage. There are un-grounded outlets in the bedrooms of the home, but as I said there aren't any devices connected to a coax. In addition, last weekend I didn't notice any issues with my connectivity and I was playing games all day Sunday as well as Monday.

I have been running ping plotter for a bit and it looks like there may be an issue with the cable in the home as my pings to hop 1 are coming back with high latency, jitter, and packet loss and I am wired directly into the modem. I know the modem isn't the issue, as this is the 3rd modem in 2 months. First two modems were ISP provided.

I took my own reading of the coax cable and I saw 6.5-7v on both the stinger and sheild.

First Hop (big outage around 8:30 and 9:15 is me testing voltage on coax).

Here is a screen shot of pinging pingplotter and google.

Pingplotter

google.com

Additional info:
Modem- Netgear CM1200
Router- Netgear Nighthawk xr450 (PC not wired to router)
-Power Cycling the modem will restore service sometimes, but usually not for more than 20 minutes.
-During severe "attacks" no amount of rebooting modem helps.
-Sometimes the issue will seem to resolve itself for a while.
-I have been told by ISP all cables between modem and telephone pole have been replaced, and the first hub has been checked and only one other home is receiving service, and they haven't reported any issues.
-Between 10AM and 4PM on day 1, all electronics not connected to PC were unplugged, and all power to appliances was turned off at the fuse box. Problems still continued.

I am at a total loss for what could be causing this, any help would be much appreciated!

Hi Hyper12,

Sorry to hear you're having a hard time with your internet connection - that sounds frustrating.

It sounds like you've already tried quite a few things to figure out where the issue is. If you have voltage on your cable line that can cause all kinds of havoc with your connection. I did a quick google search and it sounds like you can either trace where your cable comes from and check the voltage or you can call an electrician. Here is a forum thread that goes into this issue in more depth: https://www.electriciantalk.com/f2/voltage-house-coax-cable-29936/.

It sounds like you're pretty handy if you have a voltmeter and can take readings with it. If it was me I'd find where the coax comes into my house and disconnect it and check the voltage. If it has voltage then call an electrician or the cable company because there shouldn't be voltage on your coax as far as I understand.

Good luck and let us know how it goes!

Thanks,

-Poe

Hi Poe,

Thanks for the response. I took more readings both at the box out back and on the line coming into my house, both came up with no voltage. I think I was getting some "phantom readings" on my multimeter since I was inches away from the ground. This is also probably what the technician saw when he got a reading there as well. There is a grounding wire that goes across the box and acts like an antenna with the multimeter. Cable Box

I will call the cable company again tomorrow and see if they can do something else, or at least sent another tech out to see if they get a reading when the cable is pulled away from the box.

Hi Hyper12,

That sounds like a good plan!

I will say that although I'm certainly not an electrician I am pretty sure that you shouldn't have any voltage on your ground either unless you have a short to ground. If there is voltage on your ground wire I'd say it might be time to call an electrician and have them check it out just to be safe.

Good luck!


-Poe

Hi Poe,

You are correct, I have done a ton of learning about electrical over the last week and I was getting a "phantom reading". High impedance multimeters can get false readings when they are close to a ground wire. Essentially if I have just one probe of the multimeter close to or touching the ground it will read like both probes are in contact with something that has a small charge. I don't understand the science behind it, but I can get the multimeter to give me a reading on every test it can do with the exception of continuity tests.

I had an electrician walk me through some basic test to determine if the outlet's grounding was good, which we established it's very likely that it is wired correctly, and that there also isn't any voltage on the shield of the coax cable.

Guess the last technician wasn't aware of the phantom reading phenomena and just assumed his multimeter was correct, but I didn't notice where his prongs were when he showed me the reading on his multimeter.

I have the supervisor coming out next week, I will see what he has to say.

So ISP finally made it out while the issue was happening again. This time they sent in a group of 4 techs, including one area supervisor. They tested for voltage again and came up blank.

Supervisor then had them test from the utility pole, before it entered the house and they found no voltage, but packet loss inline with what I was seeing on pingplotter. I guess the installing tech was color blind or something and mistook the comcast box on the utility pole for the wave one (I guess they look almost identical) and none of the next 6 subsequent tech's noticed. ISP said they would wave fee's for the time I was having issues as well, which is nice.

Although it took them a touch over two months to fix the issue, Wave was always communicative and trying to help. In the end they sent out 1 installer and 10 tech's, and took ownership of the issue even when one tech had claimed it was voltage on the line. Overall way better service than I expected, having dealt with comcast in the past.


Here is what I was seeing and stood out to me, in case someone has similar issues in the future:
-no pattern to when loss was happening, some days would seem like they lined up but there were too many outliers to form a real pattern.
-rebooting modem usually didn't help, sometimes it would relieve attacks for a while but never for more than a handful of hours, other times no relief at all
-removing and re-attaching the coax from the modem provides same level of relief as rebooting the modem (just faster, modems boot slow)
-no voltage on the line, ISP tests with one prong to ground and the other to the coax sheild or stinger.
-Shutting off all devices in the home didn't provide any relief
-"No Ranging Response received - T3 time-out" in modem logs
-"Dyanmic Range Violation" in modem logs
-all channels on modem in the correct ranges
-internet was always full speed when it worked

Good luck to anyone having issues, thanks to pingplotter for helping me look at the issue!