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Forum Discussion
CM600 - slow speeds, is it the modem or Comcast?
Hello all, Just got a CM600 to go with my 200mbps Comcast plan but I'm only seeing speeds around 20mbps. I've tried contacting them and they've had me power cycle it, replace coax cables, etc bu...
If you have any splitters, attenuators, amplifiers in the line, remove them.
Also, check the cable for kinks, damage, bad connectors, corrosion.
Another thing you can have them do is try to re-provision the modem. It wouldn't be the first time the wrong provisioning file was sent.
If none of that works you've then narrowed the problem to either the line or the modem.
You can try exchanging the modem. The cm600 is a pretty solid modem and if you exchanged it, it pretty much points to the line or the provisioning.
Thanks for the response. I only have one cable line that enters the house and it's not split. The coax cable connected to it is fairly short and looks fine.
Ive had them reprovision the modem and reset it and that hasn't seemed to work. I guess I can try exchanging the modem and see if that helps. The modems run overnight and I see a lot more correctable and uncorrectabkes in these channels, and channel 16 still isn't locked.
| 14 | Locked | QAM256 | 37 | 609000000 Hz | 6.7 dBmV | 40.1 dB | 4 | 0 |
| 15 | Locked | QAM256 | 38 | 615000000 Hz | 6.7 dBmV | 37.7 dB | 361412 | 85 |
| 16 | Not Locked | Unknown | 0 | 0 Hz | 0.0 dBmV | 0.0 dB | 0 | 0 |
| 17 | Locked | QAM256 | 40 | 627000000 Hz | 6.7 dBmV | 29.2 dB | 63118 | 163135 |
| 18 | Locked | QAM256 | 41 | 633000000 Hz | 6.8 dBmV | 40.3 dB | 3140 | 1147 |
Hello again,
I went to target and picked up an SB6190 which seemed to completely resolve the problems after activating. Speeds were up to 200mbps as expected. After several hours speeds seemed to come back to around 20-50. I took a look at the status page and noticed something interesting. While the channels don't entirely line up (and I seem to have some more of them on this modem) it looks like the frequency ranges (615-633mhz) match up between both modems where there's an issue! I'm guessing that means the issues I'm having are not modem related. Thoughts?
Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables 1 Locked 256QAM 16 471.00 MHz 6.00 dBmV 38.98 dB 0 0 2 Locked 256QAM 17 477.00 MHz 5.90 dBmV 40.37 dB 0 0 3 Locked 256QAM 18 483.00 MHz 6.20 dBmV 38.98 dB 0 0 4 Locked 256QAM 19 489.00 MHz 6.10 dBmV 38.98 dB 4 0 5 Locked 256QAM 20 495.00 MHz 6.10 dBmV 38.98 dB 9 0 6 Locked 256QAM 21 507.00 MHz 6.00 dBmV 38.61 dB 0 0 7 Locked 256QAM 22 513.00 MHz 6.00 dBmV 38.98 dB 0 0 8 Locked 256QAM 23 519.00 MHz 5.90 dBmV 38.98 dB 0 0 9 Locked 256QAM 24 525.00 MHz 5.90 dBmV 38.61 dB 15 0 10 Locked 256QAM 25 531.00 MHz 5.90 dBmV 38.98 dB 8 0 11 Locked 256QAM 26 543.00 MHz 5.90 dBmV 40.37 dB 0 0 12 Locked 256QAM 27 549.00 MHz 5.90 dBmV 38.98 dB 0 0 13 Locked 256QAM 28 555.00 MHz 6.20 dBmV 38.98 dB 1 0 14 Locked 256QAM 29 561.00 MHz 6.20 dBmV 38.98 dB 2 0 15 Locked 256QAM 30 567.00 MHz 6.20 dBmV 40.37 dB 0 0 16 Locked 256QAM 31 573.00 MHz 6.10 dBmV 38.98 dB 0 0 17 Locked 256QAM 32 579.00 MHz 6.30 dBmV 38.98 dB 0 0 18 Locked 256QAM 33 585.00 MHz 6.50 dBmV 38.98 dB 0 0 19 Locked 256QAM 34 591.00 MHz 6.40 dBmV 38.98 dB 1 0 20 Locked 256QAM 35 597.00 MHz 6.60 dBmV 40.37 dB 0 0 21 Locked 256QAM 36 603.00 MHz 6.60 dBmV 38.61 dB 0 0 22 Locked 256QAM 37 609.00 MHz 6.80 dBmV 38.98 dB 2 0 23 Locked 256QAM 38 615.00 MHz 6.60 dBmV 38.61 dB 301 24 24 Not Locked ---- 39 621.00 MHz ---- ---- ---- ---- 25 Not Locked ---- 40 627.00 MHz ---- ---- ---- ---- 26 Locked 256QAM 41 633.00 MHz 6.90 dBmV 37.30 dB 65505 57591 27 Locked 256QAM 42 639.00 MHz 6.70 dBmV 38.90 dB 0 0 28 Locked 256QAM 43 645.00 MHz 6.70 dBmV 39.50 dB 1 0 29 Locked 256QAM 44 651.00 MHz 6.40 dBmV 39.20 dB 2 0 30 Locked 256QAM 45 657.00 MHz 6.40 dBmV 39.20 dB 0 0 31 Locked 256QAM 46 663.00 MHz 6.40 dBmV 39.50 dB 2 0 32 Locked 256QAM 47 669.00 MHz 6.40 dBmV 39.50 dB 2 0 - thoughts are you're probably correct, I'd have the isp check the line since its happening with 2 different brand of modems.