Cablecard - Mitsubishi Electric LT-37131 Service Manual

Cable
Air
in
Cable providers send QAM64 and/or QAM256 through the
coax cable to the TV's tuner. Once converted to IF it is demodulated
to an MPEG transport stream (TS). If a card is present in the
PCMCIA slot the TS will be passed to the card and returned back to
IC8506 and then finally sent to the Xilleon processor. If there is no
card present in the card slot and the tuner is tuned to a QAM channel
the TS will pass directly from the POD interface IC directly to the
Xilleon for processing.
SYMPTOM
No channel map appears when pressing
guide button (TVGuide disabled)
1
Channel map does not change after card is
2
installed. (still showing basic cable map)
Host ID screen does not appear
3
Error code received on screen. Error codes
are listed such as 161-x
4
Individual channel cannot be received.
5 (example HBOHD is no video and no audio
but other HBO channels are OK)
Certain tier of channels is not received.
6 (example: Premium channels or all HD
channels not received)
Unable to tune to a channel. (example:
7 Pressing 1055 has no response and stays on
current channel)
When using SA card channels changing
automatically and random message about
8
upgrade in process. (Channels are often like
10,000 to 50,000)
Periodically encrypted channels become
9
unavailable.
Only Analog channels can be viewed. All
digital/encrypted channels are unavailable
10
ChannelView does not list program content or
11 channel call letters
MODELS: LT-37131 / LT-37132 / LT-46131 / LT-46231

CableCARD

Main Tuner (TU-100)
(Cable/ATSC/NTSC)
DEMODULATOR
OOB Tuner (TU-101 )
POSSIBLE CAUSE(S)
Cable is not connected to ANT1 -or-
OOB data is not received correctly
CableCARD is not 'Initialized' within the service
providers system.
Signal and information not received by TV
Communication between TV and card is lost or
disrupted
The TV has no means to block individual
channels. Proper authorization is not received.
Authorizations to display scrambled channels are
sent via OOB data.
1055 is not available in the channel map.
Channel map is sent via OOB from the service
provider.
CableCARD firmware is out of date and being
upgraded by service provider.
Card is hung
Proper authorization is not received or TV cannot
display digital video
This information is provided in the form of OOB
data tables and is sent at the discretion of the
service provider
To Engine
XILLEON
IC8001
TS &
Data
POD I/F
IC8506
IC1500
TS &
Data
SIGNAL-PWB DM-PWB
Cable providers typically have both encrypted and
unencrypted channels. If the Xilleon receives an encrypted
TS it will ask the CableCARD to unscramble the stream. The
card will only unscramble the TS if it receives the proper
authorizations to do so. Those authorizations are received
via Out-of-Band data (OOB). The OOB contains information
about authorizations, channel maps and more.
1) Verify cable is connected to ANT1
2) Re-install/Replace CableCARD
3) Verify signal level and signal noise level
4) Contact Service Provider
5) Check TU101 for proper function/Replace Signal PWB
Contact service provider
1) Verify cable is connected to ANT1
2) Re-install CableCARD
3) Replace CableCARD
4) Verify signal level and signal noise level
1) Pull card from TV and wait 5 minutes. Then reinstall the
card and verify it is initializing properly.
2) Press INPUT & FORMAT keys on the front panel.
3) Replace CableCARD with new card
4) Try 3rd CableCARD
5) Replace DM-PWB
Contact service provider
Contact service provider
Verify OOB is locked. If OOB is locked, verify channel
should be received. If not locked, troubleshoot for OOB
failure on SIGNAL PWB and/or with service provider.
If this process continues more than 60 minutes, contact the
service provider for updated card
Unplug card or AC or perform initialize
1st test for QAM clear channel (often network channels are
provided free), if no QAM clear channel is available remove
the card and memorize channels. Verify that a digital
channel can be viewed. If known digital channel cannot be
viewed suspect SIGNAL
Contact service provider
Page 13
Data Bus
Data
Bus
PCMCIA
SLOT
TS &
(CableCARD)
Data
POSSIBLE RESOLUTIONS