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T4/T3 errors

New Poster

T4/T3 errors

Hello,

 

For months now, we've been having frequent connection drops, seemingly from T3/T4 errors.  I purchased a new modem which barely made a difference, and I'm using the closest and shortest cable from the outside box.  Is there anything else this could be but wiring issues on Comcast's end?

 

Thank you!

Expert

Re: T4/T3 errors

What do the modem's signal stats look like ? Try getting them here http://192.168.100.1 or here http://10.0.0.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

What is the exact make and model number of the modem ?




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New Poster

Re: T4/T3 errors

Hello,

 

MB7621

 

Down:

Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (d Corrected Uncorrected
1 Locked QAM256 24 525.0 -1.1 37.1 491 457
2 Locked QAM256 25 531.0 -0.8 37.0 624 217
3 Locked QAM256 26 537.0 -1.1 36.9 575 355
4 Locked QAM256 27 543.0 -1.1 36.9 513 353
5 Locked QAM256 28 555.0 -1.2 36.9 547 254
6 Locked QAM256 29 561.0 -1.4 36.9 542 273
7 Locked QAM256 30 567.0 -0.9 36.9 564 333
8 Locked QAM256 31 573.0 -1.4 36.9 553 343
9 Locked QAM256 32 579.0 -1.1 36.8 579 244
10 Locked QAM256 33 585.0 -0.7 36.8 590 210
11 Locked QAM256 34 591.0 -1.3 36.7 537 297
12 Locked QAM256 35 597.0 -0.8 36.9 511 284
13 Locked QAM256 36 603.0 -0.9 36.9 573 213
14 Locked QAM256 37 609.0 -0.8 36.9 585 226
15 Locked QAM256 38 615.0 -1.6 36.7 526 366
16 Locked QAM256 39 621.0 -1.3 36.7 530 244
17 Locked QAM256 40 627.0 -1.6 37.2 278 355
18 Locked QAM256 41 633.0 -1.4 37.1 249 360
19 Locked QAM256 42 639.0 -1.1 37.1 206 385
20 Locked QAM256 43 645.0 -1.3 37.0 251 353
21 Locked QAM256 44 651.0 -0.8 37.3 280 316
22 Locked QAM256 45 657.0 -1.0 37.1 365 244
23 Locked QAM256 46 663.0 -1.1 37.1 207 363
24 Locked QAM256 47 669.0 -1.9 37.1 227 333
Total             10903

7378

 

Up:

Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
1 Locked ATDMA 56 5120 17.3 54.0
2 Locked ATDMA 53 5120 36.5 54.0
3 Locked ATDMA 54 5120 30.1 54.0
4 Locked ATDMA 55 5120 23.7 54.0
5 Not Locked Unknown 0 0 0 0.0
6 Not Locked Unknown 0 0 0 0.0
7 Not Locked Unknown 0 0 0 0.0
8 Not Locked Unknown 0 0 0 0.0
Expert

Re: T4/T3 errors

The upstream power is too high / out of spec, and it may be intermittently fluctuating even farther out of spec. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.


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New Poster

Re: T4/T3 errors

Thank you for the reply.  Our internet went down for at least 4 hours today, by far the worst yet, and we called a tech out.  He got rid of the splitter on the outside box (internet only ATM), cleaned up a bunch of bad wiring in the shared box at the road, and things are looking good so far at least.  I noticed that it cleared up the extremely high upstream power, although the downstream power looks marginally high now?  Might that become an issue, or not really?

 

Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (d Corrected Uncorrected
1 Locked QAM256 32 579.0 8.5 37.0 0 0
2 Locked QAM256 12 453.0 7.7 37.1 0 0
3 Locked QAM256 13 459.0 8.2 37.2 0 0
4 Locked QAM256 14 465.0 8.4 37.2 0 0
5 Locked QAM256 15 471.0 8.5 37.2 0 0
6 Locked QAM256 16 477.0 8.4 37.2 0 0
7 Locked QAM256 17 483.0 8.9 37.2 0 0
8 Locked QAM256 18 489.0 8.1 37.0 0 0
9 Locked QAM256 19 495.0 8.9 37.1 0 0
10 Locked QAM256 20 501.0 8.7 37.1 0 0
11 Locked QAM256 21 507.0 8.7 35.4 0 0
12 Locked QAM256 22 513.0 9.1 37.3 0 0
13 Locked QAM256 23 519.0 8.9 37.3 0 0
14 Locked QAM256 24 525.0 8.8 37.2 0 0
15 Locked QAM256 25 531.0 9.1 37.2 0 0
16 Locked QAM256 26 537.0 8.7 37.1 0 0
17 Locked QAM256 27 543.0 8.8 37.6 0 0
18 Locked QAM256 28 555.0 8.7 37.6 0 0
19 Locked QAM256 29 561.0 8.5 37.6 0 0
20 Locked QAM256 30 567.0 9.0 37.6 0 0
21 Locked QAM256 31 573.0 8.5 37.6 0 0
22 Locked QAM256 33 585.0 8.9 37.3 0 0
23 Locked QAM256 34 591.0 8.3 37.4 0 0
24 Locked QAM256 35 597.0 8.8 37.6 0 0
Total             0 0

 

Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
1 Locked ATDMA 53 5120 36.5 44.8
2 Locked ATDMA 54 5120 30.1 44.3
3 Locked ATDMA 55 5120 23.7 44.0
4 Locked ATDMA 56 5120 17.3 43.5
5 Not Locked Unknown 0 0 0 0.0
6 Not Locked Unknown 0 0 0 0.0
7 Not Locked Unknown 0 0 0 0.0
8 Not Locked Unknown 0 0 0 0.0
Expert

Re: T4/T3 errors

Yer' good !


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