Xfinity cable internet - TV cutting out / moving my modem
January 8, 2022 4:38 PM
Sometimes, my xfinity internet is too slow to stream on my TV. I'd like to move the modem from the office to behind the TV. I tried attaching my modem to the coax behind the TV, but it didn't connect. I remember the TV port working previously, and when I moved the modem to the office 18 months ago I called a tech who sent some kind of signal to identify where my router was to make it work. I can't find any description of this situation online and am wondering if I'm hallucinating it. Does this technology exist and what is it called?
Bonus question: How do I contact the magic signal senders at xfinity again?
I'm pretty certain I'm just not overlooking the splitter box, I've done a lot of home improvement since I moved in and I would have recognized it. The xfinity tech also definitely wasn't physically here, the magic signal was sent during our call. There's one wire going in the house and four ports and that's it. I have an ohmmeter if that's helpful.
The modem is a Netgear N450 and I changed the default network name/password, I doubt the issue is someone is stealing my internet but I'll log into the router if it happens again and check.
I nominally have 50 Mbps service. I was pulling down about 10 Mbps this afternoon according to a speed test on my iphone although it usually gets 50ish at that spot. I suspect it's an xfinity service failure, but I know they'll blame it on my modem and I want to do what I can on my end before I deal with them. I'd also like to have my TV on a wired connection rather than on wifi anyhow for general security and speed.
Bonus question: How do I contact the magic signal senders at xfinity again?
I'm pretty certain I'm just not overlooking the splitter box, I've done a lot of home improvement since I moved in and I would have recognized it. The xfinity tech also definitely wasn't physically here, the magic signal was sent during our call. There's one wire going in the house and four ports and that's it. I have an ohmmeter if that's helpful.
The modem is a Netgear N450 and I changed the default network name/password, I doubt the issue is someone is stealing my internet but I'll log into the router if it happens again and check.
I nominally have 50 Mbps service. I was pulling down about 10 Mbps this afternoon according to a speed test on my iphone although it usually gets 50ish at that spot. I suspect it's an xfinity service failure, but I know they'll blame it on my modem and I want to do what I can on my end before I deal with them. I'd also like to have my TV on a wired connection rather than on wifi anyhow for general security and speed.
Check the signal levels on your modem using its webpage. You can access it at http://192.168.100.1/
If the downstream levels are much below 40dB or the transmit power is much above 50dBm, that's your problem. If you have a four way splitter, it should have a label with something like 7dB 7dB 7dB 3.5dB. Make sure whichever cable your modem is using is connected to the port with the lowest value. Better yet, remove the splitter entirely and replace it with a through connector unless you're actually using the other wires for cable TV or MoCA or something.
If your signal levels are good, the issue is probably congestion in Comcast's network. Since your modem only supports 8 downstream channels and Comcast typically has 32 available almost everywhere now, it's possible that a new modem might work around that issue. The cheapest way to figure that out is to rent a gateway from Comcast for a month and see if it fixes your issue. If it does, you can buy a 32x8 modem (or better yet a more future proof DOCSIS 3.1 modem). If not, Comcast won't be able to blame your equipment.
posted by wierdo at 5:44 PM on January 8, 2022
If the downstream levels are much below 40dB or the transmit power is much above 50dBm, that's your problem. If you have a four way splitter, it should have a label with something like 7dB 7dB 7dB 3.5dB. Make sure whichever cable your modem is using is connected to the port with the lowest value. Better yet, remove the splitter entirely and replace it with a through connector unless you're actually using the other wires for cable TV or MoCA or something.
If your signal levels are good, the issue is probably congestion in Comcast's network. Since your modem only supports 8 downstream channels and Comcast typically has 32 available almost everywhere now, it's possible that a new modem might work around that issue. The cheapest way to figure that out is to rent a gateway from Comcast for a month and see if it fixes your issue. If it does, you can buy a 32x8 modem (or better yet a more future proof DOCSIS 3.1 modem). If not, Comcast won't be able to blame your equipment.
posted by wierdo at 5:44 PM on January 8, 2022
It’s a Samsung smart TV, my phone also shows slow internet speed when the TV can’t stream. There is no splitter anywhere that I can find, and only one port has ever worked at a time.
Good to hear that upgrading my modem could be a fix even if it’s a problem on the provider side!
posted by momus_window at 6:16 PM on January 8, 2022
Good to hear that upgrading my modem could be a fix even if it’s a problem on the provider side!
posted by momus_window at 6:16 PM on January 8, 2022
There's something connecting the one wire coming into your house with at least one of the coax lines. Find that and you can certainly move the gateway somewhere else..
posted by wierdo at 6:38 PM on January 8, 2022
posted by wierdo at 6:38 PM on January 8, 2022
So, a few things: if it appears that you’re having slow speed across your network when you can’t stream (you mention your phone being slow), then that suggests a network or modem problem rather than a Wi-Fi signal strength problem (which is what moving your router closer to your tv would fix). If you have slow speeds on your phone even when you bring it close to your Wi-Fi router, then simply moving the router closer to the tv won’t help.
I can’t imagine what the “magic signal” would have been but, to my knowledge, coax jacks within the home are basically always just dumb wires. So, if the coax running in your wall is physically connected to the coax coming into your house (either by a coupler or a splitter), it will work. If it isn’t connected, it won’t.
I would poke around and see if you can find where Comcast’s wire comes into your house. Then, see if you can trace that wire and figure out how it connects up to the four other wires that run to the various parts of your house.
One possibility is if it is split too many times in your house (or run through a low quality or failing splitter), the signal will be too weak by the time it gets to your wall coax jack. You could then either try replacing your splitter or, if you only want to use one jack at a time, just use a coax coupler to connect the coax wire coming in from the outside to the wire you want to use.
posted by Betelgeuse at 7:42 PM on January 8, 2022
I can’t imagine what the “magic signal” would have been but, to my knowledge, coax jacks within the home are basically always just dumb wires. So, if the coax running in your wall is physically connected to the coax coming into your house (either by a coupler or a splitter), it will work. If it isn’t connected, it won’t.
I would poke around and see if you can find where Comcast’s wire comes into your house. Then, see if you can trace that wire and figure out how it connects up to the four other wires that run to the various parts of your house.
One possibility is if it is split too many times in your house (or run through a low quality or failing splitter), the signal will be too weak by the time it gets to your wall coax jack. You could then either try replacing your splitter or, if you only want to use one jack at a time, just use a coax coupler to connect the coax wire coming in from the outside to the wire you want to use.
posted by Betelgeuse at 7:42 PM on January 8, 2022
There is no splitter anywhere that I can find, and only one port has ever worked at a time.
I will admit that this confuses me. If there’s only one line coming into your house, Comcast should not be able to activate or deactivate individual jacks/ports without coming into your house and physically connecting or disconnecting wires. I suppose there may be something that exists like a “smart splitter” that allows them to remotely turn on or off jacks, but I have never seen or heard of one and my Xfinity internet is just a single wire going into a dumb splitter that I’ve connected and disconnected as needed when I’ve moved my cable modem around.
posted by Betelgeuse at 7:51 PM on January 8, 2022
I will admit that this confuses me. If there’s only one line coming into your house, Comcast should not be able to activate or deactivate individual jacks/ports without coming into your house and physically connecting or disconnecting wires. I suppose there may be something that exists like a “smart splitter” that allows them to remotely turn on or off jacks, but I have never seen or heard of one and my Xfinity internet is just a single wire going into a dumb splitter that I’ve connected and disconnected as needed when I’ve moved my cable modem around.
posted by Betelgeuse at 7:51 PM on January 8, 2022
When I moved into my house, the cable technician found that there was a lot of dead coax line in the house, not connected to the live line coming into the house. Could have been from an antenna, or previous installations, or just lines that had issues. I agree with the previous poster that moving the modem from one cable location to another shouldn’t cause issues, although I’ve found that it sometimes takes several minutes for the modem to work when I’ve reconnected it.
posted by coldhotel at 7:11 AM on January 9, 2022
posted by coldhotel at 7:11 AM on January 9, 2022
Thanks all! I am also perplexed by the lack of a splitter, my neighbor’s house is a mirror image of mine built at the same time, and it does have a splitter box outside where I just have one cable, so maybe the other lines are dead and my memory is atrocious. I’m not prepared to open up the wall to see what’s in there. Sounds like trying a better modem is the next step.
posted by momus_window at 6:45 PM on January 9, 2022
posted by momus_window at 6:45 PM on January 9, 2022
Does your TV have an Ethernet port? If it does, then connecting to the Comcast "gateway" (which is usually a combination cable modem and router) via Ethernet cable would be more reliable and probably faster for streaming.
I'm not having your issue but hooked my computers up via Ethernet to solve some speed issues. Another thing that really helped - a tech came out and measured signal strength, determined something was "off" and installed a powered amplifier for the cable. It is inside the house, it's pretty small, it plugs into an outlet and coax runs from the wall to it and then to the TV but it apparently amplifies the signal to all the coax lines in the house. In any case, it solved a lot of intermittent outage issues for us.
posted by TimHare at 7:01 PM on January 9, 2022
I'm not having your issue but hooked my computers up via Ethernet to solve some speed issues. Another thing that really helped - a tech came out and measured signal strength, determined something was "off" and installed a powered amplifier for the cable. It is inside the house, it's pretty small, it plugs into an outlet and coax runs from the wall to it and then to the TV but it apparently amplifies the signal to all the coax lines in the house. In any case, it solved a lot of intermittent outage issues for us.
posted by TimHare at 7:01 PM on January 9, 2022
Follow up - I rented a modem from Comcast and it solved the problem, so I recently bought my own 32x8 DOCSIS 3.1 modem and it's working great. Thanks for solving my rather scattered question, hivemind (and wierdo in particular)!
posted by momus_window at 2:00 PM on March 19, 2022
posted by momus_window at 2:00 PM on March 19, 2022
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posted by jonathanhughes at 4:44 PM on January 8, 2022