I have had Xfinity for a few months, working fine with my SB6141 modem until two days ago. At that point the downlink connection went to almost zero (0.05M reported by speed test, connected directly to modem, no router) while uplink connection still seems relatively stable (3-5M). The signals on my modem seem fine:
Signal to Noise Ratio 38 dB 38 dB 38 dB 38 dB 38 dB 38 dB 38 dB 38 dB
Downstream Modulation QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256
Downstream Power Level 7 dBmV 7 dBmV 7 dBmV 7 dBmV 7 dBmV 7 dBmV 7 dBmV 7 dBmV
Upstream
Symbol Rate 5.120 Msym/sec 5.120 Msym/sec 5.120 Msym/sec
Power Level 48 dBmV 47 dBmV 47 dBmV
Upstream Modulation [3] QPSK [3] 64QAM [3] QPSK [3] 64QAM [3] QPSK [3] 64QAM
Ranging Status Success Success Success
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Resetting to default and rebooting the modem make no difference. The only peculiar thing in my log is the following:
Apr 19 2014 18:50:45 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=90:--:--:--:--:--;CMTS-MAC=00:--:--:--:--:--;CM-QOS=1.1;CM-VER=3.0;
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Also, here is the firmware detail from the modem (firmware seems a bit old for a brand new modem?):
Model Name: SB6141 Vendor Name: Motorola Firmware Name: SB_KOMODO-1.0.6.10-SCM00-NOSH Boot Version: PSPU-Boot(25CLK) 1.0.12.18m3 Hardware Version: 7.0 Serial Number: 374781328023777709020022 Firmware Build Time: Oct 29 2012 18:07:13
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Any ideas for what to try to get things working again? Or what specifically to say to customer support on the phone to avoid wasting an hours of my time on a service call? Thanks!