Modem won't sync or loses sync

I have had cable internet service from Cox for 3 years in this house. All of the sudden my modem will either not sync or lose sync after a while.

Cox said that if they come out and it is my fault they will charge me $49.

So I tried an experiment. I unhooked the modem and took it to another room and connected it. It synched immediately. The weird thing was that when I took it back to the computer and connected it. It also synched right up. I have tried this for three days now and it never fails to work. Take the modem in the other room and hook it to the cable outlet. Power it on, let it sync, unconnect it and take it back to the computer. I am then good for about 4-6 hours.

What could be going on and why does synching in the other room allow the modem to sync when I bring it back to the computer.

It is not the cable used to connect the modem to the wall outlet. I have tried different permutations of cables and outlets and it makes no difference. Also, neither of these outlets have a splitter. (No splitters in the house, in the wall? who knows?)

Reply to
tabby55
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Please supply your modem make/model and your connection settings/power levels from the modem's status pages. Also a diagram of your cabling including cable type (RG6/RG59) and splitter models would help. If your transmit levels are high, you may have a cabling problem exacerbated by that 100+° AZ heat or maybe your modem is overheating.

Reply to
$Bill

x Power 52.5 dBmV Rx Power -12.2 dBmV Downstream SNR 37.2 dB Tx Frequency 19600000 Hz Rx Frequency 579000000 Hz

It is a Terayon TJ715x

Dr. Modem has examined your modem. Dr. Modem's Diagnosis: # The modem is fully operational. # Upstream Power level is high (52.5) and Downstream Power level is low (-12.3)

I have no splitters in the house that I know of. However, the outlet I use in the bedroom for the cable modem is on the other side of the wall from the living room, where the TV is connected. None of the other outlets share a wall (they are all on exterior walls) Perhaps there is a splitter in the wall?

Here is the event log:

2006/06/12 18:37:37 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:37:37 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 4.

2006/06/12 18:39:40 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:39:40 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:39:40 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 1.

2006/06/12 18:40:59 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:40:59 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:40:59 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 4.

2006/06/12 18:42:00 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:42:00 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:42:00 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 3.

2006/06/12 18:43:16 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:43:16 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:43:16 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 2.

2006/06/12 18:44:56 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:44:56 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:44:56 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 1.

2006/06/12 18:46:17 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:46:17 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:46:17 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 3.

2006/06/12 18:47:34 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:47:34 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:47:34 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 2.

2006/06/12 18:49:00 82000200 16 Critical No Ranging Response received - T3 time-out. 2006/06/12 18:49:00 82000300 1 Critical Ranging Request Retries exhausted 2006/06/12 18:49:00 85000200 1 Critical UCD invalid or channel unusable

- T3 timeout: Giving up on UCD 4.

1970/01/01 00:00:20 68000100 9 Critical DHCP FAILED - Discover sent, no offer received - DHCP init timeout! 1970/01/01 00:00:03 2242905932 1 Notice SNMP Poll - Eth Link Up. 1970/01/01 00:00:14 68000100 1 Critical DHCP FAILED - Discover sent, no offer received - DHCP init timeout! 2006/06/17 10:45:24 2242905917 1 Notice SNMP Poll - Mac Link Up. 2006/06/17 10:45:24 2242905786 1 Notice SNMP Poll - DS Link Up. 2006/06/17 10:45:24 2242905803 1 Notice SNMP Poll - US Link Up. 2006/06/17 10:45:24 2242905723 1 Notice SNMP_AGENT_COLD_START
Reply to
Culican

Your TX is on the high side - higher than I'd like and the RX is low. Either the CableCo needs to kick up the signal or you need to upgrade your cable/connections.

I have a TJ715 - here's my current numbers which are so-so :

RF Parameters Parameter Value Units Tx Power 48.2 dBmV Rx Power -2.8 dBmV Downstream SNR 32.3 dB Downstream MER 31.5 dB Tx Frequency 33000000 Hz Rx Frequency 705000000 Hz

1) Take a look at your interior cable and see what is written on it (RG6/RG58/RG59). Look inside your wall plates and see what sort of devices are there. 2) If you have a TV and a modem, there must be a splitter somewhere unless you have two lines coming in from the pole. Trace back to the entry into the house and see what's there.

Normally you would have a grounding block and a splitter (presumably 1 leg for each cable run). You would want the modem on it's own leg (you can split the TVs further down the line if necessary, but not the modem).

Check that all your connections are tight and corrosion free - I'd replace RG58/59 if it goes to your modem with RG6 - it's probably OK for your TVs.

Here's an example from my house (haven't gotten around to replacing RG59 to the TVs yet, but they work OK) - you should make one of these up for your house :

/-- Grounding block pass thru connector (grounded to electrical box) | | RG6 Terayon Netgear PC1 PC2 | /------> TJ715 Modem ----> RP614 Rtr ------|---|---|---| V /

--------->X----->X to Family Room (below) -->

| RG59 |-----------------> BR1 TV | RG59 \\-----------------> BR2/3 TV (terminated)

RG59 /-----------------> TV1 Family Room /

-------------X TV2 | RG59 |-----------------> TV3 | RG59 |-----------------> VCR1 | RG59 |-----------------> VCR2 | RG59 |-----------------> VCR3 | RG59 |-----------------> PC1 | RG59 \\-----------------> (terminated)

Reply to
$Bill

I watched the tech when he installed the whole set up 3 years ago. I seem to recall that one cable comes underground from across the street (one of those cylindrical Cox boxes there). At my box on the outside wall there was a splitter and 4 cables leading into the house, one for each outlet.

I will definitely check all of the items you said.

Thanks

I am kind of disappointed in Cox. When I called support the guy had no clue about my modem; said that since it was not synched he could not check anything. Didn't tell my about logging into it and getting the numbers, etc. I found all that out on Google (as well as the password to get into the modem.)

BTW: My modem was out of sync for several hours. I wanted to get online so I was going to move it to the other room where it works. I screwed in a 3 foot piece of cable into the wall outlet, went back to get the modem and ...yes you guessed it, it was synched. Why would a three foot stub of cable screwed into another outlet allow the modem to synch? I checked the numbers and they were better than the ones I previously posted but still too high up and too low down.

Thanks again.

Reply to
Culican

You may want to terminate any unused legs off your splitter.

Reply to
$Bill

Have you tried simply power-cycling the modem? I ask because despite all the details you've given us, you haven't mentioned doing this very simple action. If you haven't even been power-cycling the modem, I'd have to say the reason it works after moving it is that you're power-cycling it when you move it.

As for the possible charge if it's your fault, that's just a standard disclaimer to keep people who are looking for free computer troubleshooting, or people who re-wire their house, and screw everything up from getting something for free. If you haven't made any changes to the cabling since the tech originally installed you, you won't get charged for a problem with the symptoms you're describing.

It very much sounds like you need a tech, and you are not even close to being the kind of person they need to charge. Call back, and set-up an appointment. The longer you wait, the longer you'll have to wait to get a time window you like.

Reply to
Warren

Do you know a good source for those terminators? I get blank stares when I ask...

Thanks,

--Gene

Reply to
Gene S. Berkowitz

Any electronics store - Fry's or possibly Radio Shack. Just a plain old

75 ohm F-type coax terminator - they're like a dime (10/$1) or so. You'll want to find them locally since postage will cost multiple times the cost of ten of them. If your ISP comes out, ask them for a few or go to their office and ask.
Reply to
$Bill

Okay, should have done one at a time but both items are next to each other.

After being out all day, I came home and checked: modem not synched. (Event log shows lost synch at 10:23 this AM and never regained.)

I opened the Cox box on the side of my house to look, one line from across the street into the splitter and four out, into the house. This means each outlet inside is fed directly from the outdoor splitter Jiggled, all were tight. Jiggled a heck of a lot more to cram the cables back in the box and get it closed.

Read something else on Google regarding bad grounds in dry (And AZ has been parched this whole year) weather when the ground dries out. As suggested I dumped water on the ground where the cold water feed for the house enters as the house ground is strapped directly to the pipe.

Went inside, modem was up and running.

Was it the jiggling of the cable, was it the water or was it voodoo?

Reply to
Culican

Radio Shack no longer carries them. I'd be surprised to find them a Fry's, too. You'll have to go to a real electronics parts shop, not a store aimed at the mass consumers.

Reply to
Warren

I checked Fry's website and they have them online, but shipping is a lot more than the price of the terminators.

Reply to
$Bill

Scroll down 'til you find them. Free shipping.

CIAO!

Ed N.

$Bill wrote:

Reply to
Ed Nielsen

At $.55 per in lots of 10, there should be free shipping. ;)

Reply to
$Bill

May have been voodoo, but more likely jiggling of the cables. Sometimes (if there is not a good weather/water seal), the copper on the center conductor will react with water and form an oxide material that is non-conductive. If you pull the connectors off the splitter, look for a black or darkly discolored center conductor. While this is a little less of a problem in dry climates, it does happen everywhere.

Depending on what the splitter is made out of, the corrosion of the metal may of caused a "diode effect" which will basically block RF from getting across the connection. These sorts of things are usually hard to detect because any movement of the connectors will usually eliminate the diode, at least for a little while.

Of course, it could be something as simple as the coax pulling out of the connector, or a pinched coax line. Open up the splitter and check to see if the center conductor is shiny and sticking up a little bit (

Reply to
Eric

How are your power levels now ?

Reply to
$Bill

Tx Power 53.5 dBmV Rx Power -10.9 dBmV Downstream SNR 36.5 dB

Very marginally better Rx, actually worse Tx. But I haven't lost sync in almost a week now. Maybe I should actually pull the cables off the splitter and plug them back in.

Reply to
Culican

What are your cables ? RG6/58/59 ? How long are the runs (esp modem) ?

Did you find a grounding block out there prior to the splitter (or maybe the splitter is grounded) ? What kind of splitter and what do the markings indicate for Db loss ?

If all your cabling looks good and connecters are tight, Cox should come out and clean up your signal gratis.

Reply to
$Bill

"$Bill" wrote in news:bOednYFU2KkanADZnZ2dnUVZ snipped-for-privacy@adelphia.com:

the width of a dime, or nickle if it is the drop from across the street. What you want to do is get a 2 way splitter from anywhere, make sure it is 1G rated. Cox OC uses to transmit Data on 453 Mhz or was it 654 (?). Anyway, use the 2 way to split the drop to the 4 way or new 3 way and the cable modem leg, terminate the old modem leg with a 75ohm terminator. The modems autorange, they keep climbing in transmit power until they hit the CMTS with the proper signal strength. Pulling the RF (RF reset) resets this range back to a default level and that is what you are probably seeing as a synced signal.

Reply to
steve

"$Bill" wrote in news:EeKdnQvzm_5kowvZnZ2dnUVZ snipped-for-privacy@adelphia.com:

Get a 75 ohm resistor and an F85 barrel fitting (threaded both ends) stick the resistor into the barrel fitting and bend the other lead over until it touches the threaded part (case) solder into place, put on end of small jumper out of wall or unused splitter leg. Cox will replace it when they see it. If you want Cox to come out, tell them the ground wire in the prewire has come loose, they will respond to this.

Reply to
steve

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