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Hello,

I have a Vizio LED TV (2016 D-Series model) as well as cable TV (Cogeco in Ontario Canada). I noticed that when I go from an SD channel to an HD channel or visa versa, my TV goes blank for a second. I was just wondering if that "SD/HD switching" is harmful for the TV (hard on the TV set) in any way?

Thank you in advance.
 

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This used to happen on my parents Rogers cable HD Box when I set the video resolution output to "passthru". it was not harmful but some times when changing channels too quickly, it would lead to the TV to change resolutions too many times and would often get confused and end up on a black screen because the input resolution of the tv and the outputting channel of the STB were mis-matched. This all fixed when I set the resolution to a steady setting such as 720 progressive this fixed the issue or switching to HD Analog component also fixes the issue.
 

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Don't know which Vizio TV the OP is using but it's probably a 1080p panel. With Cogeco cable, 1080i would likely be a better option.

One advantage to having HD and SD channels use different output formats is automatic aspect ratio switching. Some TVs will remember different aspect ratios for different input formats so it could be set to stretch or zoom for SD channels and maintain a normal picture for HD.

Another advantage to using pass-through format mode is that the TV may perform better video scaling than than the typical cable box.
 

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the problem with Rogers was that when you set it to use pass-through and let the TV change resolutions and aspect ratio, the Rogers guide will be stretched to fill the screen when your tuned into a SD channel, but when you tune to an HD channel, the guide is proper aspect and has the black bars on the sides, not just that but the picture quality of the ipg (guide) also looks terrible on an sd channel compared to an hd channel. We experimented with this when we first got our rogers hd box but my parents quickly hated it and would rather let the STB upscale the picture than the TV.
 

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1. The OP's question was regarding Cogeco.

2. The (Rogers) Passthrough option was only available on SARA firmware, not Navigatr. Not many people with SARA firmware any more...
 

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It looks like the best advice is to try different resolutions to see which works best. I've found that it depends on the cable box and TV combination.
 

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pass thru option is outdated and being removed from newer boxes because of the glitches I mentioned and people should stop using it immediately.
The op's question was posted in: HDTV: High Definition Television including LCD and Plasma and is not limited to cogeco set top boxes and not limited to Visio TV's either. Rogers sara set top boxes experience the same problem, and its recommended to set a fixed resolution, thats why the newer boxes dont have pass thru no more.
 

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The main reason that newer (HD) boxes don't have passthrough is because the IPG/menu is now HD and is sent out as a single resolution.
 

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There is no reason why passthrough wouldn't work with HD guides and menus. It would just mean the box would switch resolution to HD when on an SD channel. Overlays might be an issue. Glitches in the TV are really a non-issue since the end user can just disable passthrough if they occur.

I see it as a dumbing down of consumer equipment in general and the NextBox in particular. Some companies tend to take features away to make development and support costs cheaper. Many consumer devices with new features are more automated with fewer options. Just look at HDMI to see how that can be done well. We saw some dumbing down with the NavigatR interface though it was done very poorly. The end result was more bugs, alienated customers due to lost features and probably more support costs. A well executed rollout would have seen the opposite.
 

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I have had the luxury of using many TV providers in North and Central America over the years: In my experience, the most common setup is to leave the set top box to output one fixed resolution for All Channels, regardless if you watch HD or SD programming. Watching a 4x3 SD station but having your box output to a higher resolution such as 720p 16x9, you would get a consistant picture when changing channels, you would also get a proper aspect ratio and have the recommended ability to use the STB's menus to change or zzoom the aspect ratio instead of the TV. I have Bell Satellite and it works beautifully, I watch a SD channel and it remembers my aspect ratio (I usually put 4x3 with grey bars on the sides, I put a HD channel and it fills the screen beautifully.)
 

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Bell Satellite boxes handle different formats well. They remember separate aspect ratios for HD and SD and automatically adjust. Other boxes (such as Rogers Cable NextBox in Ontario) do not adjust an SD aspect ratio or size correctly nor do they remember settings for different formats. They they also don't have format pass-through. There basically is no solution that works well without adjusting the TV aspect manually every time an SD to HD or HD to SD channel switch is made. Like I said, it all depends on the source equipment and TV.
 
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