Maximum PC

I think I'm having similar symptoms that the OP had, but I think it may be my modem, a Surfboard SB5120.

About a year ago, I had issues with my connection randomly being lost. Comcast came out and the tech checked the lines and told me he tightened some connections. It worked fine for a while but lately, it's been cutting out randomly again.

I tried cycling the power on everything (unplugging the modem and routers, then plugging them in one by one) but that doesn't seem to help. I need to try changing the cable between the modem and my wireless router but I don't think that cable is too old so I doubt that will address the problem.

I don't think it's my router because I can connect to the router regardless of the internet being down. I noticed today, though, that when the internet goes down, I can't connect to the modem's internal page. Right now, though, I can and here is the status page:

Downstream Value
Frequency 591000000 Hz
Signal to Noise Ratio 39 dB
QAM QAM256
Network Access Control Object ON
Power Level 6 dBmV

Upstream Value
Channel ID 2
Frequency 38000000 Hz
Ranging Service ID 99
Symbol Rate 2.560 Msym/s
Power Level 43 dBmV

So, long story short, is there a way I can test the modem's health myself without going through Comcast? If I need to replace the modem, should I just get another Motorola SURFboard SB5101 or maybe a D-Link DCM-202?

Thanks in advance.

Roadrunner runs the test from their side, the modem belongs to RR, it is part of the subscription.

So when it went bad, dropped download speed to 1/2, plus they were upgrading anyway, they replaced it.

What Comcast can/will do for you, I can't answer that, if phone support is bad, do they offer chat?

Probably the modem itself is locking up.
The signal values from it (when you're able to access it) look ok...

If it's TW's modem, call them. If it's yours, it's time to get a new one.
However, a service call wouldn't be a bad idea, if you can make the time for the tech. They typically don't charge for this sort of thing.

It's my modem so any repairs are on me. The reason I'm hesitant to call them is because when I called them a year ago, they told me that if they determine the problem is on my end (such as my modem going bad), then I'm responsible for the service visit. That's why I'd like to eliminate possibilities on my end first.

You said the values "look ok". Is that "ok" meaning "could be better" or meaning "they are acceptable"?



Is there a test I can do from my end? I remember them calling my modem last time and they pulled up the same information I posted here. I think they also reset the modem. Is that all they would do?

If I replace the modem, what should I get? The D-Link DCM-202 has good reviews. The only major downside I can determine is that it seems that its support cycle is waning (as well as some complaints of it having a 2 year life, where my current Motorola's lasted 3.5 years). The Motorola SURFboard SB5101 also has good reviews. On the plus side, I can get the OEM version for $10 cheaper than the D-Link. While their speed values are different, neither would bottleneck my connection, so could there be any advantage to the D-Link?

I believe the D-Link has a 1 year warranty while the Motorola Retail has a 2 year warranty (I'm not sure about the OEM, though I know they're usually shorter).

Thanks.

I replaced my modem today with a Comcast provided modem (and I also used the Cat5 cable that came with it to hook from the modem to the router). It seems like the problem hasn't cleared up. I want to give it a day or two to be sure (in case it takes some time for the modem to "settle in" -- something I doubt but it's worth a shot). The trouble is, that I'm at a loss as to what the problem could be.

Before replacing the modem, I did an online tech support chat and they told me that there seems to be a signal problem and it's usually caused by the connection, the modem, or the router. Obviously, the modem's been removed from this equation now. I'm unsure as to why a router would cause trouble with the signal but when my connection goes down, I can access the router but not the modem. I haven't tried connecting the modem directly to a computer but will soon.

One thing I'm curious about but haven't tried (for the same reason I haven't tried connecting a computer directly to the modem), is that if I unhook the cable from the wall (so not the Cat5e cable, but the one from the wall to the modem), would I be able to connect to the modem by typing in its IP address?

First, to clear something up:
TW and Comcast got mixed up earlier in the thread. TW doesn't charge for diagnostic service calls; Comcast, OTOH, charges for everything. My bad on the mis-read.

Back to your issue:
New modem (and, from Comcast), and 'net still goes down, modem admin page not accessable.
Can you move the modem from its current location, to the first termination after your cable entrance? This will (dis)prove your in-home wiring as being the cause of the issue.
And, yes, it wouldn't be a bad idea to try connecting one of your PCs directly to the modem for testing. This will also (dis)prove the router as being the failure point.
Note that you'll need to power down the modem for at least 10 minutes before starting the 'test PC' (modem needs a power-cycle to reset itself.)

At this point, though, I'm thinking janky cabling at some point (either in your house, or up to the pole.)

The signal values that you posted earlier are very acceptable. However, that doesn't mean that they aren't fluctuating. If you can't get at the mdem's admin page when service goes out, how would you know if the signal is still OK?

The tech I spoke to online said that if it's determined to be my equipment that's causing the trouble, then it'll be $50. If it's their equipment, then it's free.

The only Comcast cable jack in my home goes into the room where the modem is. There is a cable going directly from the wall jack to the modem. I can try replacing that cable (though it was provided by Comcast so I would think that if that's bad, then it's on them...but I could be wrong).

I'll be trying this tomorrow (or maybe Saturday). The problem is that the cable modem shares a room with my infant daughter (it's a small house so it's unavoidable) so I need to mess with it while she's awake.


I think they are fluctuating but I'm not sure by how much. Too bad I don't have this modem unlocked like my old one (the one I just replaced). The only page I can access just has some basic info though it does include the power levels. I can't access the log or anything else. I still can't access the modem when the net goes down. I'll have to try unplugging the RG6 cable from the modem and see if I can still access the modem's admin page. That would also help removing the router as a problem, though I doubt that's the problem since it's only about 2 months old and this problem predates it. It's hard to say how bad it was with my old router since that one would also lose the wireless connection (which is why it was replaced) but I do know some of the connection issues had the same symptoms as they do now.

Anyway, I'll post updates as I try things.

So are you running the network over wireless then? What router are you using?

Now, to clarify a few things because either I missed it, or it didn't get said here. When you say it drops the connection, is the connection light on the MODEM still on, or does it turn red or go out? I'm beginning to think you have a wireless problem, and not a modem problem, seeing as how you can't access the modem at all.

It's a straight, uninterrupted run (no splits) from the entrance (where the cable comes into the house) to that room? Wow - that's, well, odd.

Oh, one other thing to take a look at: there's typically a grounding block on the outside of the house - these are good for corrosion problems, worse if the cables aren't very-well-terminated, and/or if the original installer didn't configure it properly.
Installed right, the service drop, ground block, and entrance cable should form a W, with the block at the middle (this encourages water to flow away from the block.)
It wouldn't be a bad idea to take that apart (if present), see if it's crusty, and maybe connect the modem directly to the service drop.

I only pay Comcast for the internet. I have DirecTV for my TV. That's why it's a direct run without any splits. Outside of the house there is a spot where there was a split but that was removed so there is a connection point between two different cables.

I think I know where you're referring to. I'll take a look during daylight.

Sorry, I missed your post before responding to Cup.

I'm running a network with wireless and wired. One computer is plugged directly into the router, one is over the wireless. If the internet goes down with one computer, it simultaneously goes down for both. (I'm talking about the internet itself, not the network. Sorry if that sounds snarky, it's not intentional) I can always connect to the router's admin page, it's the modem's admin page that I cannot always connect to. The lights on the router and the modem all stay on as normal (from what I can tell).

Still, to eliminate the possibility that it's a problem with the router, I will be connecting one of the computers directly to the modem. I'll be trying that tomorrow if I'm still having connection problems (I'm trying to give the modem at least a night to see if it just needed some time).

Ya, that's why I'm asking about it. If the internet light on your modem stays on, or doesn't change to red, it's almost making me wonder if it's your router that's lost communication with your modem. When this issue happens, have you tried resetting JUST the router? I'm just suspicious, especially after the tech has been out twice, a new modem has been installed, and your STILL having issues.

Anyways, just wanted to get that bug out of my system. Go ahead and follow cup's advice about hooking straight to the modem for a day or two and see if the problem continues. When you hook straight to the modem, you'll need to reset the modem, then possibly your PC, before it will work properly.

I forgot to add that on at least one occasion (and I think a few times), I unplugged everything and then plugged everything back in one by one, giving each time to get itself set up. It didn't seem to make a difference.

Also, I've only had a tech out once and that was about a year ago. I'm trying to eliminate possible sources of trouble on my end so that Comcast won't charge me.

Ah, gotcha. Those little details I need to learn to remember. Anyways, yeah, try hooking directly to the modem. That will eliminate or prove the router as an issue.

Something else I just noticed. You said there USED to be a splitter, and now there is a butt splice. I would try taking it apart and see if there is any corrosion/moisture/funky stuff going on there. If so, clean it up. I should also mention that sometimes butt splices do weird things with coax. Is it possible for you to run a whole new line from the house to the cable box, thereby eliminating that butt splice?

I'll be checking that splice tomorrow when I check the rest of the connections. I think if a new line needs to be run, I'll let Comcast do it. When I moved into my house, it was their tech who left it that way. Theoretically, I could do it myself but that would require tools I don't have (such as the tool to cut and add a new connector to the RG6 cable as well as materials to attach the cable to the side of my house which is stucco and can chip easily).

In bold you will find part of the problem (I think) at least the system I work in above 5 on the DS is to high. We do also use 591mHz for HSD everythingelse looks good as far as your levels go.
Either model you are talking about should be fine with comcast.
If the problem continues I would have them send a tech out and tell the tech the DS is a bit high and see what he can do to bring it down a bit. Those levels though may not be off within Comcast's system. I just know that with Cox in So Cal things are just a bit off and can be corrected.[/b]