VIZIO openQAM decoding problem on Cox Phoenix? - AVS Forum
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post #1 of 18 Old 02-24-2010, 07:59 AM - Thread Starter
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Cox points finger at Vizio and Vizio points at Cox. What to do?

I have Vizio GV47L and a Sony. The wall outlet has +6dB signal from COX.
Both TV scan analog and digital channels. But VIZIO displays black screen on all digital channels, while Sony has no problems at all.
VIZIO grabs enough of the information to know the numbers and names of digital channels but apparently does not have enough information to decode them.

Is it VIZIO or COX?

How to resolve this issue?

PS> the telephone call to Vizio was a waste of time - they employ script readers who are incapable of recognizing technical issues. They say things like: :if you can receive normal channels than it means the TV works", or "If you can see DVD playing - the TV tuner is fine", "The TV has only one tuner" etc etc.
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post #2 of 18 Old 02-24-2010, 08:50 AM
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I have no trouble with clear QAM channels from Cox Orange County with my Vizio VF550My Vizio after a scan will show both the analog and digital version of a local broadcaster. For example it will list both channel 7 and channel 7-1 and I can select either one and either one will play without problem.
Have you checked the program mode settings you are using for the internal tuner to be sure that there is no setting that would prevent digital HD resolution content from being displayed?
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post #3 of 18 Old 02-24-2010, 10:57 AM - Thread Starter
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Quote:
Originally Posted by walford View Post

I have no trouble with clear QAM channels from Cox Orange County with my Vizio VF550My Vizio after a scan will show both the analog and digital version of a local broadcaster. For example it will list both channel 7 and channel 7-1 and I can select either one and either one will play without problem.
Have you checked the program mode settings you are using for the internal tuner to be sure that there is no setting that would prevent digital HD resolution content from being displayed?

Thanks for your input. There is nothing in the program setting that would prevent any program to display - it would be in the parental lock setup.
As I stated the scan does find digital signals but it does not show detect them.
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post #4 of 18 Old 02-24-2010, 11:48 AM
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So are you saying that the digital channels such as 4-1,5-1 or 7-1 are deteted at scan time but are not shown from the list of available channels when you try and watch one of them or are you sayinng that when you select one of them from the list that it will not play video or audio?
Have you tried using a different Vizio program mode for your TV tuner as teh source then the one you are using now?
Are you using a spliter to feed separate input in to the Vizio and in to the other TV?
If yes have you tried bypassing the splitter and going direct to the Vizio to increas not only the signal to noise ratio but also the signal strenght?
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post #5 of 18 Old 02-24-2010, 12:08 PM
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I have 2 Vizio's at home, they have no problem decoding the local Time-Warner clear QAM's, nor my 2 locally inserted QAM channels. Nor do the Vizio's I have here at work have any problems with TWC and the 8 locally inserted QAM's here.

However, The problem can easily be a combination of both. MPEG encoding and transports and receiver-decoder incompatibilities caused by software or local configuration issues can be finicky at times.

Bob

The views expressed here are my own and do not necessarily represent those of the FOX,ABC,CBS,or CW Networks,MeTv, my employer or its parent company. Nor my wife for that matter!
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post #6 of 18 Old 02-24-2010, 03:39 PM
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I have a Vizio and sometimes it takes 2 or more attempts to tune a channel before it will lock on. Sometimes it repeatedly gives a blue screen with "no signal". Vizio is one of the crappiest digital tuners out there. They are prone to occasional freeze-ups requiring unplugging the power. Direct entry of RF channel number is not allowed either. The only thing in theri favor is they scan very quickly and reject encrypted channels.

How can we say "the digital transition is complete" when thousands of low power stations are still broadcasting in analog?
LOW POWER ANALOG NEEDS TO DIE NOW!!!
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post #7 of 18 Old 02-24-2010, 03:50 PM - Thread Starter
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Thank you for your input.
The Vizio does scan and does list the digital channels e.g. 3.1,5.1,12.1, 12.2 and in the hundreds etc., but when it comes to show the picture it does not decode them ever.

There is no "undue" splitters and the signal was measured to be +6 dB which is more than enough - cable company checked all out with a very impressive meter. As the result their finger pointed out to Vizio.

Vizio by the way gave me the telephone numbers to two of their authorized repair centers: one never answered the call, the second first took my name and number and a day later called me with the demand that they must diagnose the TV first; they wanted to diagnose by talking to me on the telephone and they wanted to charge $25 for that.
Now I am convinced that it was an error to buy Vizio - originally I thought it was suspicious that they never update their TV firmware - now I think it came full circle. VIZIO is crap! now you all know it too.
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post #8 of 18 Old 02-24-2010, 06:59 PM
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Quote:
Originally Posted by m44 View Post

VIZIO is crap! now you all know it too.

I won't quite agree, but close....however I think a common consumer reports saying definitely applies here: "There Are Better Choices"

I have a Toshiba that locks up regularly and needs power cycling, so Vizio isn't the only one.

Bob

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post #9 of 18 Old 02-24-2010, 07:53 PM
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my 2 cents: its an issue with the vizio. if your sony gets the channels, then the cable is fine. is the tv still under warranty through vizio?
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post #10 of 18 Old 02-24-2010, 08:40 PM
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You should re-post this in the Phoenix HDTV forum, I have a Vizio 32" with Cox and had no issue getting all the unencrypted QAM channels including locals such as 3.1, 5.1, etc. as well as WGN-HD(121.1). I now use a Tivo w/CC and tuning adapter so don't use the QAM tuner in the set anymore. But one of the frequent posters in the Phoenix local forum has had issues with his Vizio and how it decoded Cox QAM channels as well.
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post #11 of 18 Old 02-25-2010, 08:06 AM
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I bellieve that there is no problem with the tuner in the Vizio and that it is finding and recieving all of the analog and digital channels from your basic Cox cable service.
What does appear to be a problem with your Vizio is that the circuit that process digital signals after receipt for display is not working, possibliy the chip in the digital circuits that decodes and decompress the digital signals has failed which would therefore result in blank displays.
How long have you had your Vizio GV47L? Has it ever been able to receive and play either OTA digital channels or clearQAM digital channels? I ask these questions there may actually be some aspect of the Cox digital signals in Phoenix that are not compatible with older model Vizio digital signal processing electronics but are compatible with newer model Vizion digital processing circuits.
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post #12 of 18 Old 02-25-2010, 01:33 PM
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Have you tried moving the Vizio TV to where the Sony is located and hooking it up there using the same cable the Sony is using? There could be a problem with the cable running to where the Vizio is located (old splitters, frayed cable, etc.).
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post #13 of 18 Old 02-25-2010, 03:14 PM - Thread Starter
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Thanks.
As to OTA: Vizio is scanning, naming and actually displaying content with some freezing on some channels - it most often happens on 12.1
But the same numbered channels only scan/name from the cable source.

It is interesting. Since the channels numbers taken from the OTA and cable are the same - what is the difference in the signal from OTA and Cable that the tuner (or other circuit) cannot handle?
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post #14 of 18 Old 02-25-2010, 03:17 PM - Thread Starter
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This Vizio is manufactured Dec 2006.
It does scan and nicely receive the OTA channels.
Exactly the same numbered channels from Cox Cable source only scan/name and do not show content.
I could not get from either Cox nor from Vizio any explanation as to signal differences or causation of this.
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post #15 of 18 Old 02-25-2010, 03:18 PM - Thread Starter
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Yes - Vizio does not work on any signal on which Sony works.
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post #16 of 18 Old 02-25-2010, 05:52 PM
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Based on your updates, especialy the fact that the Vizio can receive an display OTA 8VSB protocol digital programs, it is apparent to me that the Vizio digital display circuit either thinks that all QAM protocol digital programing it is actually receiving from Cox is encrypted or it is unable to display QAM digital content from Cox for some other reason. Other users in your area with Vizio tuners with QAM capability are not having the same problem since there TVs are newer and therefore have different QAM digital processing circuitry.
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post #17 of 18 Old 02-26-2010, 07:37 AM
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My two Vizios (both built late '06) developed this problem in January. I'm on Comcast cable in the Detroit area.

In my case though, the Vizios also lost the OTA digitals.

(My Dvico Fusion PC tuner still works just fine.)

Both sets were grandfathered under Costco's perpetual satisfaction guaranteed policy so the local store manager agreed to swap my 42P for a new Vizio since they couldn't get it repaired in time for the Superbowl. This new Vizio still works fine, both OTA and QAM.

A new main board (w/ tuner) was put in my 37L last week. It scanned and displayed OTA just fine. But on the cable, it put about 80 digitals in the scan with the correct channel numbers but just displayed black screen for all digitals.

Later I tired OTA again and now it only displays black for the OTA digitals. Rescanning doesn't do a thing! It zips through the digital scan in about one second leaving the scanned channels unchanged. Analogs are fine in both modes.

Vizio/Costco is bringing out another main board but now say I may need an adapter (they are bringing one) to get digitals from the cable, blaming the problem on changes made by Comcast.

I'm going to try to get more info from Vizio (perhaps a written statement?) about this issue, an will keep things posted.

Dave
on Comcast Cable of Canton, MI
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post #18 of 18 Old 03-12-2010, 10:00 AM
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The dust has finally settled on this issue. Apparently Comcast changed something in the way their DTV was being sent out which caused the firmware which displayed the digital output of the Vizio ATSC tuner to become permanently confused, rendering the set unable to display any digital channels, whether OTA or QAM.

At Costco's expense, ITI (Vizio's USA service rep) twice replaced the main board in one of the TVs only to experience the same failure after performing a cable scan. Vizio confirmed that the faulty F/W was not upgradeable on these boards.

Vizio makes no claim that Comcast has done anything wrong.

Costco has swapped out my TVs (a 37 LCD and a 42" Plasma) with new Vizios at no cost to me (both sets were "grandfathered" under Costco's unending satisfaction guaranteed policy). The new sets are working fine, both OTA and QAM.

The moral of the story - if you have an older model Vizio that is working fine OTA and/or via a STB trying a Comcast cable scan is like playing with fire!

Dave
on Comcast Cable of Canton, MI
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