I am pretty certain I know the answer but wanted additional validation. I purchased an Arris S34 because my old Motorola MB8600 was having some issues and figured I might as well go with the latest with improved uploads. Initially the Arris S34 worked great and I was getting upload speeds of 320mbps which was impressive but would then lose connection after 30 minutes and rarely reconnect on a power reset. After dealing with Xfinity offshore level 1 tech hell for several days I had another tech come out to my house who indicated the tap box needed to be replaced. I reconnected my MB8600 and ran the Spectrum Analyzer. It's noisy and uneven. Around 400 MHz and again near 950–1000 MHz. Above 950 MHz, the signal sharply falls off to the noise floor.
Screenshot:
(edited personal information)
Event log:
Time Not Established
Critical (3) CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established
Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=(edited personal information) :72;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established
Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established
Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established
Critical (3) CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-85MHz.
Time Not Established
Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established
Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established
Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
09:52:36
Mon Sep 15 2025 Critical (3) CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
09:52:38
Mon Sep 15 2025 Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
09:52:38
Mon Sep 15 2025 Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
09:52:38
Mon Sep 15 2025 Critical (3) CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
09:52:41
Mon Sep 15 2025 Critical (3) UCD invalid or channel unusable;CM-MAC=(edited personal information);CMTS-MAC=00:90:f0:4d:02:00;CM-QOS=1.1;CM-VER=3.1;
09:52:43
Mon Sep 15 2025 Notice (6) Honoring MDD; IP provisioning mode = IPv6
09:52:51
Mon Sep 15 2025 Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
09:52:51
Mon Sep 15 2025 Critical (3) CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
09:52:51
Mon Sep 15 2025 Critical (3) CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
09:52:58
Mon Sep 15 2025 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=(edited personal information);CMTS-MAC=00:90:f0:4d:02:00;CM-QOS=1.1;CM-VER=3.1;
09:53:07
Mon Sep 15 2025 Critical (3) UCD invalid or channel unusable;CM-MAC=(edited personal information);CMTS-MAC=00:90:f0:4d:02:00;CM-QOS=1.1;CM-VER=3.1;
Does this all sound about right and match up? Any additional suggestions or experiences?
