Series 3 Dropouts

[zombie]

Hello All,
I recently purchased a Series 3 from Weaknees with the largest hard drive upgrade available at the time (100hr HD). Nice unit, cool service. However, I am experiencing occasional, almost frequent, audio dropouts followed by some video scrambling when watching recorded HD programs. The severity of the vidoe scrambling seems related to the length of the audio dropout.
This problem seems not uncommon since I've read about it on other forums (including Tivo's own)
I'm getting my HD programming OTA using an amplified antenna and according to my units own signal strength meter, signal is excellent.
Whats going on with this? I'm afraid its ruining my Tivo experience.

[WK-Michael]

Obviously, that shouldn't happen.

If you repeat the part of the program that has dropouts, does that occur again in the same place?

[zombie]

Yeah... seems like the dropouts are recorded with the show. You know, we watch a lot of HD programming. Sometimes record 2 HD programs while watching a third. Is there some kind of buffer underrun issue at play here?

[WK-Michael]

No - it's not likely that. It's likely a CableCARD or tuner problem. Does it happen only on HD shows? Encrypted channels? OTA broadcasts?

[zombie]

We don't have any cable cards. All our HD programming is OTA. So the only time we notice the problem is while we're watching HD OTA recorded programs. Our signal strength here is generally excellent, living in Pasadena, below Mt. Wilson. Check out these forums for more descriptions of the same issue.

http://www.tivocommunity.com/tivo-vb/showthread.php?t=316896&page=1&pp=30

http://www.tivocommunity.com/tivo-vb/showthread.php?t=316896&page=9&pp=30

http://www.tivocommunity.com/tivo-vb/showthread.php?t=330221

http://www.tivocommunity.com/tivo-vb/showthread.php?t=316896

[WK-Michael]

So have you tried blocking out individual channels?

[zombie]

Blocking individual channels? I don't get it. Which ones? Channels that exhibit dropouts? Blocking them from being recorded? That would certainly solve the problem...

[WK-Michael]

Sometimes a 'toxic channel' can cause these problems. You might try blocking the worst channel and seeing if that fixes others.

[moraga695]

I too have dropouts. The are very similar to what zombie (and others) describe. I receive all my HD via cable cards as opposed to OTA. One channel is much worse than others with a dropout occurring approximately every two minutes. Another HD channel has dropouts but they occur much less frequently. All the other HD channels are essentially dropout free.

Since I also have a cable company HD DVR, I chose the worst channel (local NBC HD) and recorded yesterday's Sunday night football game on my Series 3 and on the cable DVR. Results: Series 3 had the usual dropouts every couple of minutes - cable company's DVR had NO dropouts at all!

Like zombie, my signal strength is good so I don't think that's the issue.

moraga695

[zombie]

I searched the Tivo forums a little more and found that OTA NBC channel 4.1 is considered a "Toxic channel" Recording this channel causes machine restarts, and apparently a host of other problems. Apparently Tivo is aware of this problem. There is also a lot of hope on the forums that a software upgrade (8.1) will fix some or all of these problems. I plan to stop recording NBC 4.1 and record NBC off of analog cable (not HD) and see if my problems go away. Of course, recording non HD shows off analog cable is not the reason I spent all this money on Tivo but, we'll see...

[WK-Michael]

OK - please report back on how your 4.1-less TiVo behaves!

[zombie]

Well, I was in the middle of changing my Season Passes etc. to record my favorite NBC shows in low resolution crappy cable and I just couldn't do it!
I switched on NBC 4.1 and turned on the signal strength meter.
After watching for a while I noticed that the meter would occasionally dip slightly below 70, at which point the picture would tear. I checked other stations and they all seemed to stay above this threshold. Anyway, rotating the antenna slightly got the meter to stay in the eighties so, I'm going with this theory for now.

[WK-Michael]

OK - sounds like a good theory. Tell us how it goes.

[moraga695]

Since my Tivo S3 was updated to firmware version 8.0.1.c, the dropout problem I was having appears to be over!

I just recorded Sunday night football from my cable company's HD feed of our local NBC channel and there were no sound or video dropouts. In contrast, last Sunday (with 8.0.1b) the same program had dropouts every one to two minutes (which had been standard for that channel since I got my S3).

Count me as a happy camper!

[zukworld]

I've been trying to track this down for a few weeks. I never noticed it previously, but now it affects recordings every day.

The channels affected vary, time of day varies, it doesn't seem to be only HD channels as Animal Planet is affected.

Our workaround is to schedule a new recording of any show that has the problem. We rarely watch live.

However today I saw it happening and was able to look at the Diagnostic page.

On the problem tuner (0 in this case), signal strength and signal lock kept changing to a blank. The problem stayed on that tuner, even though I changed away from CBSHD (311 on comcast in Houston) until I got to a different digital channel (302 FOXHDSW- in sign off, displaying just colorbars), then the tuner was fine. (I was able to repeat this behaviour several times.) The other tuner was able to tune 311 with no problem, but if I went back with tuner 0, then bingo, dropouts and pixelation.

This continued for several minutes. At the moment I can tune 311 on tuner 0 w/out problems.

Update!- just a minute later, 311 on tuner 0 is showing the problem again, and I have the same problem as I channel change away until I get to Fox's "good" signal. Then I can go back to the "bad" channels and they are fine.

So, is the signal "poisoning" tuner 0? Is the signal intermittently bad? (if so, why have the problem on only one tuner?) Any other ideas?

I have 8.3.1 on my 300 hr (stock) Series 3. Tuner 0 shows signal strength of 84 or 86 when it is able to correctly tune 311. (I can't tune 311 with tuner 1 at the moment, 'cause tuner 1 is busy recording one of my wifes shows, so I can't compare the signal strenghth on the same channel with the different tuners.) I can't rule out a physical problem with the different tuners. I can't rule out a problem with the signal. Any further t-shooting I can try the next time I see the problem?

thanks,z

[WK-Michael]

Definitely try using the other tuner. That should determine whether or not it's a tuner issue or a signal issue.

[zukworld]

I had more time to look at it this afternoon. The second tuner also has the problem when on other channels, and when I look at the Diagnostic page, I can see the "signal level" go blank and bounce around between 74, 86, 92, etc, and "signal lock" change to "NO".

I guess this means it's a signal level issue. Complicating the troubleshooting, one tuner may be slightly better dealing with the low signal.

It was definitly happening on a variety of channels including Bloomburg, some HD, and some SD.

I guess my next step is Comcast. I hate the idea of waiting around for them, but I'm glad my beloved Tivo may not be to blame. Although it seems really strange that the signal level varies so much over time, and by channel.

z

[Heathdc]

I've had the same trouble on several channels. Signal starts out good, but after a couple minutes starts going bad. Had Cox come and check it out. The signal is pixilating and audio dropping out. Tivo shows signal dropping and coming back. The Cox meter on the line shows a strong signal throughout. Cox says it is a tuner problem, not cable card.

[WK-Michael]

I've had the same trouble on several channels. Signal starts out good, but after a couple minutes starts going bad. Had Cox come and check it out. The signal is pixilating and audio dropping out. Tivo shows signal dropping and coming back. The Cox meter on the line shows a strong signal throughout. Cox says it is a tuner problem, not cable card.

Sounds like they're right. Is the unit from us?

[Steve7124]

Has anyone talked to Tivo about this issue? Frankly after paying $800 for a Series 3, I dont think I should have to block channels or worry about which tuner is stronger.

[WK-Michael]

I think TiVo would swap it out, as would we . . . No one is suggesting you'd have to live with the problems.

[Steve7124]

So is the general feeling it's not a Tivo software issue that will be corrected by a new release? I get both the sound drop outs as well as pixelation in the middle of a recorded show..in fact on occasion it pixelates then skips further in the show so that I miss part of it. I was almost thinking that perhaps there was a problem on the hard disk of the unit...is there a way to have the unit do a disk scan and block any bad sectors? I remember on my old series 1 there was a code you could enter and it would scan and reformat the disk.

[WK-Michael]

We haven't seen it to be a temporary problem associated with a specific software version, no.