Comcast HDTV-Signals dropping out

Archived from groups: alt.tv.tech.hdtv (More info?)

My hdtv audio and video signals sometimes freeze, pixelate, or drop out
altogether, then resume for a while until it happens again. It seems to
happen after I've been watching a program for a while.

Is this normal? Could it be a problem with my Motorola set top box
(5100)?

Thanks!

Archived from groups: alt.tv.tech.hdtv (More info?)

Or you just could be getting a poor network or Comcast signal. We (in
Phila.) get similar problems randomly on almost all network channels
through the Comcast HDTV box. After four tech visits, nine calls,
etc.. we just chalk it up to Comcast/networks. The latest has been the
audio getting unsynchronized from the video (audi leads). It happens
during a commercial and usually continues for the rest of the show.
When the next show starts its better. Usually on one channel. And
Comcast nevers knows what's happening until the next day. Switching to
the analog channel eliminates the problem but its still on the digital
channel. If its not annoying just ignore it for now and maybe next
year DirecTV or Verizon will have a better system for a few dollars
(ha!) less.

Archived from groups: alt.tv.tech.hdtv (More info?)

I'm in the Philly suburbs and see this happen also.

A few weeks ago, I was watching "24" on Fox's HD channel, and it kept
freezing, for minutes at a time. I had to switch to the non-HD channel.
Then I would flip back to the HD channel after a while - sometimes it would
be back, sometimes it would still be frozen. If it was back on, it would
eventually freeze again.

It's been OK the last few weeks, but it was acting a little strange last
night again, with the picture occasionally scrambling for a second or two,
but it never froze.

(And I wish Comcast would get on the ball and update the menu system on the
HD boxes. I have a non-HD box on another TV with the new menus and I like
them a lot better than the toy-like old menus still on the HD box.)


"Howard" <howard@energytactics.com> wrote in message
news:1109111699.970034.137240@o13g2000cwo.googlegroups.com...
> Or you just could be getting a poor network or Comcast signal. We (in
> Phila.) get similar problems randomly on almost all network channels
> through the Comcast HDTV box. After four tech visits, nine calls,
> etc.. we just chalk it up to Comcast/networks. The latest has been the
> audio getting unsynchronized from the video (audi leads). It happens
> during a commercial and usually continues for the rest of the show.
> When the next show starts its better. Usually on one channel. And
> Comcast nevers knows what's happening until the next day. Switching to
> the analog channel eliminates the problem but its still on the digital
> channel. If its not annoying just ignore it for now and maybe next
> year DirecTV or Verizon will have a better system for a few dollars
> (ha!) less.
>

Archived from groups: alt.tv.tech.hdtv (More info?)

Seen this a lot in the Detroit market, seems to be a combination of signal
quality, actually cable quality (connections, etc.) and specific model of
the decoder boxes being used.
"Naz Reyes" <user@site.com> wrote in message
news:X5Odner0WYDidobfRVn-3w@comcast.com...
> Dennis N. Yugo wrote:
>
>> My hdtv audio and video signals sometimes freeze, pixelate, or drop out
>> altogether, then resume for a while until it happens again. It seems to
>> happen after I've been watching a program for a while.
>>
>> Is this normal? Could it be a problem with my Motorola set top box
>> (5100)?
>>
>> Thanks!
>
> I've seen this happen twice with my SA3250HD STB through Comcast. I'd
> guess that Comcast was having technical difficulties on their end, since I
> haven't seen it happen on my STB in about 2 days.
>
> -Naz

Archived from groups: alt.tv.tech.hdtv (More info?)

I've seen this too on my Comcast HD cable (using the Motorola DCT6208
box). After watching for a while, I noticed that the dropout/breakup
seems to occur during a big change from a light to dark scene, or the
other way around. And the problem seems to be worse on the higher
quality HD channels

I'm wondering if the cable box gets overloaded when the video bit stream
can't be compressed sufficiently (the image is changing too much). Ie.
a burst of high bit rate info is too much for the box. I think I
remember reading something in this newsgroup about certain HD cable
boxes having problems with high bit rate HD channels.

Anyway, I had a Comcast tech come out. He said my signal strength was
very strong (but not too strong).

I complained to Comcast via my local government cable franchise
management office. The problem then seems to have miraculously gotten
better (although Comcast hasn't told me that they fixed anything). I
wonder if Comcast cleaned up the signal somewhere upstream of me?

Typically Comcast blames dropouts on a weak signal, but I wonder if
strong, but noisy signals also degrade quality?

Degradation might typically be compensated for by error correction info
built into the digital video stream, but in a marginal situation, a
burst of high bit rate info (rapidly changing scene) might overload the
error correction.

These ideas are almost totally, but not quite entirely, pure speculation.

Ben in DC
PublicMailbox at benslade dot.com
(append 030516 to the subj to bypass spam filters)
"In theory, there is no difference between theory and practice. But, in
practice, there is."
Jan L.A. Van De Snepscheut


Dennis N. Yugo wrote:
> My hdtv audio and video signals sometimes freeze, pixelate, or drop out
> altogether, then resume for a while until it happens again. It seems to
> happen after I've been watching a program for a while.
>
> Is this normal? Could it be a problem with my Motorola set top box
> (5100)?
>
> Thanks!

Archived from groups: alt.tv.tech.hdtv (More info?)

Diablo wrote:
> I've had OTA HDTV here in Los Angeles since 2000. Usually, the picture and
> sound are outstanding. However, the pixelization, freezes, lock-ups, and
> loss of signal have always been a periodic and frustrating problem. I
> attributed this to poor weather or other atmospheric conditions. I use an
> indoor Radio Shack double-bowtie antenna that I sometimes have to shift a
> bit to get a good signal. Last summer, I also got the Comcast HD/PVR box.
> I thought my problems would be resolved since I figured that Comcast would
> have a direct feed from the networks rather than pulling a signal off Mt.
> Wilson 20 miles away like I do OTA -- but NO! I've been continuously
> frustrated that the Comcast signal has the same problems that I get OTA. If
> it weren't for the HD stations that Comcast receives that I can't get OTA
> (HBO, ESPN, INHD1 & 2, Discovery), I would tell them to take their box back.
> But since it only costs me $5/month extra, I don't sweat it. I continue to
> use OTA as well since Comcast doesn't carry all the local stations in HD
> (UPN, WB, KCAL, PBS Multicast, ABC Multicast). So, bottom line -- it
> probably isn't the box -- its probably the network feed. I'm just surprised
> that it isn't better through Comcast.
>
> On Tue, 22 Feb 2005 06:23:20 -0800, Dennis N. Yugo <number6@oncebitten.org>
> wrote:
>
>
>>My hdtv audio and video signals sometimes freeze, pixelate, or drop out
>>altogether, then resume for a while until it happens again. It seems to
>>happen after I've been watching a program for a while.
>>
>>Is this normal? Could it be a problem with my Motorola set top box
>>(5100)?
>>
>>Thanks!
>
>
I experienced this problem with one channel on my HD cable. The cable
service guy fixed it by replacing the cable's connector (plug). Said
that a little corrosion was the problem.