Equipment:
-Hitachi 42" plasma, 1024x1024 native resolution. When I got it last summer on clearance, out of the box the PQ was OK in HD, but awful with SD channels. So I bought AVIA calibration disc and set all the settings custom so that the HD was even better and the SD was much, much improved and watchable.
-Cox HD-DVR service

Problem:
- In recent weeks, the PQ took a dive on both SD and HD channels. HD isn't quite as clear or crisp and there's more hints of pixelation than there should be. SD channels, however are about as bad as they were when the TV was out of the box. Fuzzy, jaggies, and heavy pixelation. It's at the point now where I'm really considering cancelling cable altogether. No color problems... just bad looking due to pixelation, fuzziness, and lack of sharpness.

My Thoughts:
- Leading up to the problem, several times I would turn the TV on and it would be on a cable channel input instead of HDMI input as it always does. I figured the TV just must have reset, because all the the TV settings- tint, color, contrast, sharpness, and customized color settings were all default. I fixed them as I had them written down on the manual and thought I solved the problem. But no, that made just a slight difference. All TV settings are exactly the same as they've been since I set them up a week or two after getting the TV and Avia disc.

- So I thought the problem was either COX, HDMI cable, or the TV but unsure which. I hadn't watched a DVD in a while, but last weekend I rented Harry Potter and Order of the Phoenix on standard DVD. I popped it into the upconverting DVD player, and was disappointed in the PQ. I've watched plenty of DVDs from older movies to TV shows and new movies and it's always looked VERY good, near the PQ of watching network shows in HD. So I thought "damn, that means the problem isn't Cox, it's either my TV or the cable". The PQ on Harry Potter was better than SD channels on Cox, but not as good as previous DVD viewings and HD channels.

- This weekend I rented two movies b/c nothing was on I was tiring of watching very bad SD channels. I rented I am Legend and Cloverfield. The PQ of both was very good, like it had always been with the upconverting DVD player. So good, that I didn't even notice until after watching the two movies that there was any picture quality problems. So, I came into work this morning and checked the trusty DVDTalk review for standard DVD version of the Harry Potter movie and found it to mention the below average PQ in the video department of the review. Now, I'm thinking this no longer a TV issue or HDMI cable issue, but a Cox issue.

-My next step would have been to buy a new HDMI cable b/c I only have one and only one HDMI input on the TV. But the PQ with the two latest movies were back to "very good". I checked the settings on the Cox HD-DVR- it's the same... it upconverts to 720p while on SD channels, same as before. There aren't really any other video settings other than setting 480i/480p/720p/1080i, and it converts to 1080i while on HD channels.

So.... has my thinking been so far correct? That b/c I experienced a much higher quality PQ through DVD player with the same HDMI cable and HDMI connection on the TV, this has to be a Cox issue? It's going to be worthless calling them, as all they will say is "did you unplug it? let me refresh your converter box. OK let me schedule someone to come out" and all the technician will say is "yeah the SD picture is bad b/c you're stretching it". Yeah, I know that..... I'm just saying its much worse than it was a month ago but the tech didn't see it a month ago. So before I start going in that circle with them.... anything I may be missing?

I would suspect the cable company as well. Not sure what you can do unless you can switch to FIOS or satellite

There are no new cable boxes. They are the same 12 that have been around since 1973. They just keep giving them back to other people, occasionally replace an internal part to make it look like they are trying. Maybe you can get one that's been updated this decade if you keep calling.

Hmm, the one I have is relatively new... it's new model number than the previous one I had and supposedly has a slightly larger hard drive (the cable box itself is bigger than the one I had) and I had to wait on a list. But I've had it for 6 months now without (many) problems.

So it definitely sounds like problem on Cox's end, either the signal or the cable box?

My guess is the signal. How many other cable jacks are in your house? Do you also have Cox for internet?

Yep, we've got Cox internet. We haven't noticed any problems with it, but we rarely use it. Just very occasional internet surfing or checking something online after work.

we have 3 other TVs, but we don't have a cable box for any of them. The channels on those are the same as they've always been... haven't noticed anything with those. But I'm not sure if I could tell, the PQ on those have always been below average as analog.