I'm grasping at straws here, and reaching out to a
wider community to find out if there's anyone out
there that's been able to get an HWIC-CABLE-D-2
card to work. I figured it was worth giving one
more shot before I call and cancel my Comcast
account, as it seems silly to pay for a service I
can't use.
The card synchronizes with the CMTS system,
does all the happy dancing back and forth with
ranging, etc. and then just hangs waiting for the
TFTP transfer to complete. Tried different cables,
removing all splitters, plugging in right at the entry
point to the facility...no change. 
Here's the config on the interface:
netflight-1841#show run int cable-Modem 0/1/0
Building configuration...
Current configuration : 344 bytes
!
interface Cable-Modem0/1/0
ip address dhcp
no ip redirects
no ip unreachables
no ip proxy-arp
ip nbar protocol-discovery
ip flow ingress
ip nat outside
ip virtual-reassembly in
load-interval 30
service-module ip rip relay
ipv6 address dhcp
ipv6 dhcp client pd hint ::/60
ipv6 traffic-filter v6-external-in in
no cdp enable
end
netflight-1841#
netflight-1841#show int cable-Modem 0/1/0
Cable-Modem0/1/0 is up, line protocol is down
HFC state is IP_COMPLETE, HFC MAC address is 0018.19b6.76f6
Hardware is Cable modem, address is 001b.2a7d.adfc (bia 001b.2a7d.adfc)
Internet address will be negotiated using DHCP
MTU 1500 bytes, BW 10000 Kbit/sec, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not supported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/17/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
30 second input rate 14000 bits/sec, 19 packets/sec
30 second output rate 0 bits/sec, 0 packets/sec
HFC input: 0 errors, 0 discards, 0 unknown protocols 0 flow control
discards
HFC output: 0 errors, 0 discards
49900914 packets input, 3803706540 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicasts)
0 runts, 0 giants, 5 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
34567 packets output, 1519738 bytes, 0 underruns
0 output errors, 0 collisions, 5 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
netflight-1841#
netflight-1841#show controllers cable-Modem 0/1/0 mac state
Connectivity State: IP complete
Boot State: Waiting for TFTP
BPI Security: Disabled
DOCSIS Operating Mode: DOCSIS 1.0 mode
DOCSIS COS Mode: Unregistered
Snmp Operating Mode: NmAccess mode
MIB Values:
Mac Resets: 0
Sync lost: 0
Invalid Maps: 0
Invalid UCDs: 0
Invalid Rng Rsp: 0
Invalid Reg Rsp: 0
T1 Timeouts: 0
T2 Timeouts: 0
T3 Timeouts: 1
T4 Timeouts: 0
Range Aborts: 0
DS Lock : Locked
DS Frequency: 651000000 Hz
DS QAM Mode: QAM256
DS Power Level: 4.3 dBmV
DS Symbol Rate: 5360.537 Ksym/sec
DS Interleave: 32 Taps, 4 Increment
DS SNR: 38.3 dB
US ID: 45
US Frequency: 18900000 Hz
US QAM Mode: QPSK
US Power Level: 35.7 dBmV
US Symbol Rate: 2560 Ksym/sec
Ranging Offset: 12226
Mini-Slot Size: 4
Change Count: 1
Preamble Superstring:
03 f0 28 33 eb f0 28 33 eb f0 28 33 eb f0 28 33
eb e1 ee 16 6d e8 73 09 15 d7 92 e7 03 ba 7a 94
0a af ad 06 ed ac 17 7c 79 a6 b8 d1 7f 4b 14 c6
03 32 b2 7e d2 4d f9 6a 14 4e cb d8 6a 9c 86 21
00 88 c8 ea d8 e2 54 6c f9 e2 dc a4 13 3a 3e f0
7f 0d f3 de c0 ed f3 de c0 0d f3 de c0 ed f3 de
c0 ed f3 de c0 ed f3 ff ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
Burst Descriptors: