Xfinity Support

"Hello. My gateway is registering a severe downstream signal overflow (Power Level at +22 dBmV and SNR collapsed to 27 dB), but my upstream is normal at 41 dBmV. This is a local network/plant infrastructure issue affecting the neighborhood tap, not my house. Please do not schedule an in-home technician. Please escalate this directly to local line maintenance to balance the neighborhood tap/amplifier."

Note this is happening at night some time after 11:30pm, did this on 10/13/2026 and 10/14/2026

Downstream	Channel Bonding Value
Channel ID	38	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	33	34	35	36	39	40	41	37
Lock Status	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Not locked	Not locked	Not locked	Not locked	Not locked	Not locked	Not locked	Locked	Locked	Locked	Locked	Not locked	Not locked	Not locked	Not locked	Locked	Not locked	Locked	Locked	Locked	Locked	Locked	Locked
Frequency	339 MHz	387 MHz	393 MHz	399 MHz	405 MHz	411 MHz	417 MHz	423 MHz	429 MHz	435 MHz	441 MHz	447 MHz	453 MHz	459 MHz	465 MHz	471 MHz	477 MHz	483 MHz	489 MHz	495 MHz	507 MHz	513 MHz	519 MHz	525 MHz	363 MHz	369 MHz	375 MHz	381 MHz	345 MHz	351 MHz	357 MHz	630000000
SNR	35.9 dB	29.6 dB	30.3 dB	30.6 dB	30.7 dB	30.9 dB	30.7 dB	29.6 dB	28.2 dB	0.0 dB	0.0 dB	0.0 dB	0.0 dB	0.0 dB	0.0 dB	0.0 dB	28.5 dB	29.7 dB	30.0 dB	29.3 dB	0.0 dB	0.0 dB	0.0 dB	0.0 dB	27.4 dB	0.0 dB	27.6 dB	28.5 dB	33.7 dB	30.3 dB	28.4 dB	25.5 dB
Power Level	22.5 dBmV	14.5 dBmV	15.6 dBmV	16.0 dBmV	16.3 dBmV	16.9 dBmV	17.0 dBmV	16.0 dBmV	14.3 dBmV	12.7 dBmV	11.3 dBmV	10.6 dBmV	10.3 dBmV	10.5 dBmV	11.3 dBmV	12.6 dBmV	14.2 dBmV	16.0 dBmV	16.8 dBmV	16.4 dBmV	13.0 dBmV	11.8 dBmV	11.1 dBmV	10.7 dBmV	11.2 dBmV	10.9 dBmV	11.5 dBmV	12.9 dBmV	19.1 dBmV	15.2 dBmV	12.4 dBmV	15.8 dBmV
Modulation	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	Unknown	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	OFDM

*Channel ID 38 is the Primary channel

Upstream	Channel Bonding Value
Channel ID	1	2	3	4	5	6
Lock Status	Locked	Locked	Locked	Locked	Locked	Locked
Frequency	10 MHz	16 MHz	22 MHz	29 MHz	35 MHz	39 MHz
Symbol Rate	2560	5120	5120	5120	5120	1280
Power Level	42.0 dBmV	42.3 dBmV	42.3 dBmV	40.8 dBmV	40.8 dBmV	41.0 dBmV
Modulation	QAM	QAM	QAM	QAM	QAM	QAM
Channel Type	ATDMA	ATDMA	ATDMA	ATDMA	ATDMA	ATDMA

CM Error Codewords
Channel ID	38	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	33	34	35	36	37	39	40	41
Unerrored Codewords	67051285	140662995	148116862	148615407	148720916	149400239	148554050	137610995	55389371	912944	29	0	0	0	60	773152	46739526	125867145	137797971	115274771	27998	0	0	0	6176677	3504910	14657391	87132772	119929333	151193902	149348015	67051285
Correctable Codewords	77958445	10219067	2753272	2283956	2161946	1515000	2367140	13313737	88922581	8138374	0	0	0	0	0	22399102	92648129	25095462	13198238	35655699	1799534	0	0	0	60410437	43275249	82801529	62919029	14498924	2545	1856777	77958445
Uncorrectable Codewords	6106618	1323	10	6	6	1	9	2576	6535435	6955511	0	0	0	0	0	54319996	11417518	28654	1565	70457	6032920	0	0	0	43492647	40292083	47878026	1143316	102360915	0	4	6106618

Modem Stats

Modem Status:Connected

Responses

Oldest First

Selected Oldest First

EG

Expert

•

122.2K Messages

6 hours ago

Is there a drop amplifier on the coax cable line leading to the modem ? If so, try removing / bypassing it and see.

1

0

U

NO Amps on my side, overhead line straight to grounding block straight to modem. No amps or splitters and modem is the only thing connected. This is a problem in the neighborhood, neighbors have same problem at the same time. Just please check the modem logs in area and then check the area. Thank You.. also note this started with the cooler nights in my area, plus Georgia Power is replacing all the power poles on my road and in the greater area.

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Reply

5 hours ago

0

U

user_pmqlw7

Visitor

•

3 Messages

5 hours ago

This is during the day. power levels are higher than a few weeks ago. Power levels for down channels was in the -2 to +5 range plus there was no uncorrectable code word errors like there is now in the day and worst at night. during the day plan speed is there but the errors. At night 50mbps down if lucky.

Device Information

HW Version:2.5

Vendor:Technicolor

BOOT Version:S1TC-3.81.22.7

Model:CGM4981COM

Product Type:XB8

Flash Part:4096 MB

Download Version:Prod_24.2_PD & Prod_24.2_PD

Core Version:1.0

Downstream	Channel Bonding Value
Channel ID	38	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	33	34	35	36	39	40	41	37
Lock Status	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked	Locked
Frequency	339 MHz	387 MHz	393 MHz	399 MHz	405 MHz	411 MHz	417 MHz	423 MHz	429 MHz	435 MHz	441 MHz	447 MHz	453 MHz	459 MHz	465 MHz	471 MHz	477 MHz	483 MHz	489 MHz	495 MHz	507 MHz	513 MHz	519 MHz	525 MHz	363 MHz	369 MHz	375 MHz	381 MHz	345 MHz	351 MHz	357 MHz	630000000
SNR	38.1 dB	37.7 dB	37.2 dB	36.8 dB	36.3 dB	35.9 dB	36.1 dB	36.4 dB	36.2 dB	36.1 dB	36.1 dB	35.9 dB	35.7 dB	35.5 dB	35.9 dB	36.2 dB	36.1 dB	35.8 dB	35.5 dB	35.2 dB	34.5 dB	34.9 dB	35.3 dB	35.3 dB	36.2 dB	36.7 dB	37.5 dB	37.8 dB	37.3 dB	36.8 dB	36.2 dB	34.8 dB
Power Level	13.0 dBmV	12.8 dBmV	11.2 dBmV	9.9 dBmV	9.1 dBmV	8.8 dBmV	8.6 dBmV	8.6 dBmV	8.5 dBmV	8.4 dBmV	8.1 dBmV	8.0 dBmV	7.8 dBmV	7.7 dBmV	7.7 dBmV	7.8 dBmV	7.7 dBmV	7.5 dBmV	7.1 dBmV	6.8 dBmV	6.1 dBmV	6.6 dBmV	7.1 dBmV	7.4 dBmV	7.4 dBmV	8.7 dBmV	10.9 dBmV	13.1 dBmV	9.5 dBmV	7.9 dBmV	7.1 dBmV	5.7 dBmV
Modulation	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	256 QAM	OFDM

*Channel ID 38 is the Primary channel

Upstream	Channel Bonding Value
Channel ID	1	2	3	4	5	6
Lock Status	Locked	Locked	Locked	Locked	Locked	Locked
Frequency	10 MHz	16 MHz	22 MHz	29 MHz	35 MHz	39 MHz
Symbol Rate	2560	5120	5120	5120	5120	1280
Power Level	40.8 dBmV	41.5 dBmV	41.8 dBmV	41.3 dBmV	41.5 dBmV	42.5 dBmV
Modulation	QAM	QAM	QAM	QAM	QAM	QAM
Channel Type	ATDMA	ATDMA	ATDMA	ATDMA	ATDMA	ATDMA

CM Error Codewords
Channel ID	38	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	33	34	35	36	37	39	40	41
Unerrored Codewords	1265159849	2055672366	2060506410	2051395893	1931190007	1663293798	1457539817	1328150254	1256502119	1223227937	1204993353	1194804577	1191499910	1194905048	1207041864	1219684451	1248220328	1272157251	1249096051	1226470102	1193847357	1191067443	1189375337	1189752069	1245994886	1264792017	1313674832	1781479186	1567252058	2062605382	1794680583	1265159849
Correctable Codewords	87678620	6902140	2068075	11186781	130679207	329470139	350937191	298549740	141191400	73857579	61578186	55580955	54305265	57030730	69199615	148044508	263276567	274061499	194807801	128584741	50936994	49555373	49118842	50645268	47223734	59003967	122723898	277265128	878116667	89206	261646727	87678620
Uncorrectable Codewords	54541330	58	8	38	722028	68317971	131924646	203342476	151131885	48447784	38940533	29363243	32567710	34558534	44575573	193531365	259215948	230514742	175101944	95227989	33362043	26595930	25184287	27344470	26932335	34812470	105153605	3964065	607124845	0	6345000	54541330

Modem Stats

Modem Status:Connected

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user_pmqlw7

Xfinity Support

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user_pmqlw7

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