I have been experiencing some flaky modem behaviour this morning. I have an old Motorola SB4100 (connected via Belkin N1 Vision router) which has been a real stalwart for many years, but went a bit loopy earlier.
When I checked it first thing this morning the only lights on the front panel were the power and recieve (solid on) with the send light (flashing).
I tried the usual fix - powered every thing off and back on in sequence. This seemed to resolve things for about 10 mins. At that point the modem seemed to go into it's boot cycle before apparently recovering connectivity. I did a bit more net usage before it went kaboom & rebooted itself again. It did this three or four more times before I got cheesed off and left it.
I've recently done the whole power cycle thing again, and it seems to have stabilised although whether this is a false dawn remains to be seen.
I checked the VM service status page, and there was no mention of any works or such in the Swindon (SN1) area.
I've included some logs & signal status data, just incase anyone of you members who's technically savvy can see anything amiss. Fingers crossed to steady service and all that.

Thanks in advance for any enlightenment anyone can provide.
Downstream Value
Frequency 331000000 Hz Locked
Signal to Noise Ratio 35 dB
Power Level -8 dBmV The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please
Reload/Refresh this Page for a new reading
Upstream Value
Channel ID 3
Frequency 34000000 Hz Ranged
Power Level 58 dBmV
Motorola Surfboard Log Sample
Time Priority Code Message
090427131647 7-Information D507.0 Retrieved Time....... SUCCESS
************ 8-Debug F504.1 Bridge Ethernet Hook. Failed to learn CPE MAC Address.
************ 4-Error F507.5 MAC Filters. Add MAC Address can't add entry. Table is full.
************ 8-Debug M571.6 CM Cert Upgrade Enabled. Initiate via SNMP
************ 8-Debug M571.9 Missing CM Cert Upgrade TLVs.
************ 8-Debug M570.1 Motorola CM certificate required
************ 8-Debug X501.4 Provisioned Unit Update skipped. Image is current.
************ 8-Debug I503.0 Cable Modem is OPERATIONAL
************ 7-Information B401.0 Authorized
************ 8-Debug F502.1 Bridge Forwarding Enabled.
************ 8-Debug F502.3 Bridge Learning Enabled.
************ 7-Information B0.0 Baseline Privacy
************ 7-Information X519.8 Unit Update - GGFGGD - SCD flags
************ 8-Debug I500.1 DOCSIS 1.0 Registration Completed
************ 7-Information I500.4 Attempting DOCSIS 1.0 Registration
************ 7-Information D509.0 Retrieved TFTP Config File SUCCESS
************ 7-Information D507.1 Retrieved Time....... FAILED
************ 5-Warning D4.1 ToD request sent - No Response received
************ 7-Information D511.0 Retrieved DHCP .......... SUCCESS
************ 5-Warning D3.0 DHCP WARNING - Non-critical field invalid in response
************ 4-Error D530.8 DHCP - Invalid Log Server IP Address.
************ 5-Warning D520.2 DHCP Attempt# 1 BkOff: 5s Tot DSC:1 OFF:1 REQ:1 ACK:1
************ 7-Information D0.0 DHCP CM Net Configuration download and Time of Day
************ 7-Information T500.0 Acquired Upstream .......... SUCCESS
************ 8-Debug T503.1 Acquire US with status OK, powerLevel 58, tempSid 1615
************ 8-Debug T505.0 Acquired Upstream with status OK
************ 3-Critical R2.0 No Ranging Response received - T3 timeout
************ 8-Debug T503.1 Acquire US with status RR Change, powerLevel 58, tempSid 0
************ 8-Debug T505.0 Acquired Upstream with status RR Change
************ 7-Information T501.0 Acquired Downstream (331000000 Hz)........ SUCCESS
************ 8-Debug T509.0 Acquired DS with status OK, DS Freq 331000000, US Id 2
************ 7-Information I510.0 *** BOOTING *** SB4100-0.4.9.4-SCM02-NOSH
************ 3-Critical R2.0 No Ranging Response received - T3 timeout
************ 3-Critical R7.0 Unicast Ranging Received Abort Response - Re-initilizing MAC
************ 3-Critical R2.0 No Ranging Response received - T3 timeout
************ 8-Debug T503.1 Acquire US with status RR Change, powerLevel 48, tempSid 0
************ 8-Debug T505.0 Acquired Upstream with status RR Change
************ 3-Critical R2.0 No Ranging Response received - T3 timeout
************ 3-Critical R7.0 Unicast Ranging Received Abort Response - Re-initilizing MAC
************ 3-Critical R2.0 No Ranging Response received - T3 timeout
************ 8-Debug T503.1 Acquire US with status RR Change, powerLevel 58, tempSid 0
************ 8-Debug T505.0 Acquired Upstream with status RR Change
************ 7-Information T501.0 Acquired Downstream (331000000 Hz)........ SUCCESS
************ 8-Debug T509.0 Acquired DS with status OK, DS Freq 331000000, US Id 2
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 161500000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 161250000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 160750000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 160500000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 160250000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 159750000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
************ 8-Debug T509.0 Acquired DS with status NO FEC lock, DS Freq 159500000, US Id 0
************ 3-Critical T2.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing