pixellation only in some channels

[trosh]

Pixellation, slowing, audio-out, and sometimes black screen occur when cable signal is sent thru Tivo;

BUT only on PBS 11 and channel 5 (Cox Digital cable with Scientific Atlanta set-top box, Cox South, SoCal).

Picture is fine when signal routed directly to TV set from the set-top-box bypassing Tivo. When routed thru Tivo (recording or "live TV") these two channels pixellate. All other channels are fine when routed thru Tivo. Satisfactory channel change seems to be indicated and to have have occured via IR blasters.

Have tried the various levels of restart and also "kick start" routine several times; during "kick start" the "serious problem" green screen (GSOD) comes up, does it's thing, and after Tivo restarts, all is temporarily fixed with clear pictures, only to recur moments later.
Our second Tivo works just fine - no problems
This seems to indicate the cable signal is OK from the set-top-box. But what's the Tivo problem??? If dying disk, why only those two channels? Motherboard??

Sick? Tivo TCD24008A series 2 lifetime
Well Tivo TCD5400040 series 2 monthly

[ZikZak]

It's probably not sick; it's normal for all tivo recordings to be slightly pixellated. Moreover, tivo is more sensitive to defects in the signal than the human eye; it might look good to you, but be difficult to encode for the tivo.

These channels might be sending a signal that was previously MPEG encoded, and thus are slightly pixellated to begin with; tivo would amplify those effects.

I recommend: first, turn the sharpness control all the way down on your TV. That's where it belongs if your TV is younger than 20 years old (on newer TVs, the digital "edge enhancement" of the sharpness controll will hugely amplify MPEG artifacts). Second, if that doesn't solve the problem, see if a radio shack cable amplifier helps.

[trosh]

Unfortunately neither tweak worked. Neither sharpness adjustment, nor two different signal amplifiers.

Puzzling problem. Could it be MPEG decoder or other?

[nogee]

Trosh,

I have had the same experience and live in So Cal with the Motorolae Cox box. I have checked this problem into this forum and received the "your hard drive is failing" message. I have since gone through the 8.1 upgrade without a hitch and so I feel somewhat confident that my hard drive is healthy enough.

I have experienced a lot of pixelation this past summer where I could not view some channels. Even my local channels suffered. Some small pixelation is occuring now. I think the Cox box is now susceptible to heat and causes the pixelation. I don't have any problems on the pass through signal direct to my TV. A friend of miine, non-TiVo, had pixelation and was told by Cox to come in a replace the box. It cleared his signal up. I think I'm going to try the same thing. My digital Cox box is pretty old.

[trosh]

Solved problem
Appears to be due to cable signal degradation. In my case caused by faulty splitter installed outside just after the main Cox yard box. Determined by bypassing their splitter.

[ZikZak]

Glad it's working now!

[nogee]

Trosh... was this a splitter for your property so that you could have multiple sources for your house? This would be after it leaves the COX box on the street where it distributes out to other customers?

thanks