[mythtv-users] firewire trouble on SA 4240HDC

[Shawn Flynn]

> From Kirk Haines on April 19, 2008 5:21 PM
>> From Robert McNamara on April 19, 2008 2:27 AM
>>> On Sat, Apr 19, 2008 at 12:17 AM, Kirk Haines <kirk.haines at gmail.com>
wrote:
>>> I am trying to setup a Scientific Atlanta 4240HDC over a firewire  
>>> connection.  My cable vendor here in Oklahoma City is Cox  
>>> Communications.  The 4240 shows up in plugreport, but have only seen  
>>> failure with firewire_tester.  Despite that I continued with setting  
>>> up mythtv.  Once I had the backend up and running, I started the  
>>> frontend to see if by some chance I could get a signal.  Unfortunately  
>>> all I got was a blank screen with "(L__) Partial Lock" below the  
>>> channel and program title (on all tested channels: SD networks, HD  
>>> networks, SD cable, HD cable).  However, it appears to be changing  
>>> channels correctly on the 4240.  I have tried using P2P as well as  
>>> broadcast, different connection speeds, different protocols (Generic,  
>>> 4200HD, and 4250HDC still let me change channels), but to no avail.  I  
>>> receive messages from mythbackend that I have not received any data  
>>> from the firewire connection in X msec.
>>>
>>>  So now I am stuck with knowing the firewire works (since it changes  
>>> the channel), and that the firewire doesn't work (since it gives me no  
>>> video).  I can only speculate that I am having a protocol problem  
>>> somewhere.
>>>
>>>  I tried to follow the procedures outlined in the webpages below to  
>>> setup this system.
>>>
>>>  http://www.mythtv.org/wiki/index.php/Installing_MythTV_on_Fedora
>>>
>>>  http://www.mythtv.org/wiki/index.php/FireWire
>>>
>>>  I started with a Fedora 8 LiveCD to install since this machine 
>>> doesn't  have a DVD drive.  The firewall and SELinux are disabled.  
>>> Also, no  extra video drivers or audio was setup (this machine is only 
>>> to be a  backend once it is up and running).  As bizarre as it 
>>> sounded, I  followed the instructions about blacklisting the newer 
>>> (kernel
>>>  2.6.22+) firewire modules.  I am currently running the backend  
>>> manually as root in an effort to avoid any permission issues at this  
>>> point.
>>>
>>>  I have been using MythTV for about 3 years with analog cable and have  
>>> enjoyed it immensely.  I am not looking forward to the prospect of  
>>> going to some $20/mo. 'service' that Cox provides.  Any assistance  
>>> would be greatly appreciated.
>>>
>>
>> What you're describing is the behavior of a firewire box when all the  
>> channels are 5C encrypted.  Sorry, but if I had to put money on it, I'd 
>> say  you're not going to be able to capture video via firewire with your
provider.
>> To head off a possible followup question, the box is not the issue, as 
>> the  port behaviors are dictated by the headend, not the box itself.  
>> You can  try to get your provider to flash your STB with an amended 
>> policy, but  that's usually a lost cause.
>
> Thanks Robert, that makes a lot of sense for what I am experiencing.
> When trying to set all this up, I ran into many citations to FCC
> regulations regarding firewire ports and capabilities. 
> Are they legally obligated to do anything in this case, and if so what?
> Also what specifically should I ask for and what is the best way to do so?
>

It is quite easy to tell if it is a 5C problem or not. You can see the 5C
status of the channel you are watching from the diagnostics screen on the
SA4250HDC. There are two different software versions that can be run on the
4250, SARA and Passport. Since I'm only familiar with the SARA software,
I'll give you the instructions for that and leave the Passport instructions
as an exercise for the reader.

* First, hook the 4250 up to a TV so that you can see the output screen.
* Tune the 4250 to the channel you wish to check.
* On the front of the 4250, hold in the '+' or 'select' button until the
'envelope' icon on the front panel (above the time/channel display) lights.
About 2 to 5 seconds should do it.
* On the front of the 4250 while the 'envelope' icon is lit, press the
'info' button.
* You should now see a diagnostic screen overlayed on your video output.
* Press the 'left' or 'right' arrows on the front of the 4250 to cycle
through the various pages of diagnostics.
* Look for a field labelled 'EMI/CCI' on one of the pages. This is the 5C
status of the channel and it will read as 'freely,' 'once,' or 'never.'
* Press 'exit' to get out of the diagnostic screen.

If you are in the US and are tuned to a station that you would normally be
able to pick up OTA, then the EMI/CCI (5C) status should read as 'freely' in
the diagnostics screen. If it doesn't, call your cable provider and quote
the FCC documents to them. 

I would be very interested to hear what the results of your looking to the
diag screen are, as I have a 4250 that exhibits the exact same behaviour
that you described. Channel changing is flawless, but firewire_tester will
work at best once every 200 attempts, and myth always gives me the partial
lock indicator whether I am on a 'copy freely' channel or not.

Shawn Flynn