HDMI video problem
#1
HDMI video problem
Strange problem. Don't know if there is a solution, but I'm hoping for an explanation.
I use two 22" TV's as computer monitors. Screen #1 is use as the main screen and most of my computer work and usually use Firefox as the browser. It is connected via Display Port from the computer to HDMI on the TV.
The second TV is connected via HDMI to HDMI on both computer and TV.
I use both screens as en extended desk top. Both "monitors" use the full screen surface. In other words from edge to edge and top to bottom. No Problem there. I also use screen #2 as TV via Chrome browser and the Spectrum TV website. Again all good.
Here's the problem. I just purchased a 10 foot HDMI cable to replace the 6 foot cable that was a stretch to connect the computer and monitor #2. Now all of a sudden if I use the #2 TV as a TV via the web site, I'm getting an oval high-lite in the middle of the picture that fads to black as it gets to the edge of the screen. Kinda of like a photo. This does not happen using the screen as a computer monitor. Switching to Firefox as the website browser does not solve the problem. Using the #1 screen as a TV is OK.
Here is a screen shot of the problem. I'm sure its the cable but why? And can I do something about it?
Oh!, the only other thing is that the cable was purchased as an HDMI with Ethernet. They all seem to be stated that way.
I use two 22" TV's as computer monitors. Screen #1 is use as the main screen and most of my computer work and usually use Firefox as the browser. It is connected via Display Port from the computer to HDMI on the TV.
The second TV is connected via HDMI to HDMI on both computer and TV.
I use both screens as en extended desk top. Both "monitors" use the full screen surface. In other words from edge to edge and top to bottom. No Problem there. I also use screen #2 as TV via Chrome browser and the Spectrum TV website. Again all good.
Here's the problem. I just purchased a 10 foot HDMI cable to replace the 6 foot cable that was a stretch to connect the computer and monitor #2. Now all of a sudden if I use the #2 TV as a TV via the web site, I'm getting an oval high-lite in the middle of the picture that fads to black as it gets to the edge of the screen. Kinda of like a photo. This does not happen using the screen as a computer monitor. Switching to Firefox as the website browser does not solve the problem. Using the #1 screen as a TV is OK.
Here is a screen shot of the problem. I'm sure its the cable but why? And can I do something about it?
Oh!, the only other thing is that the cable was purchased as an HDMI with Ethernet. They all seem to be stated that way.

Last edited by Norm201; 01-16-19 at 03:00 PM.
#2
I'm a little hazy on how you are getting your computer feed to the second TV. I thought that took a card to do.
Anyway...... is that oval moving on the screen ?
Do the TV's have three prong plugs ?
Anyway...... is that oval moving on the screen ?
Do the TV's have three prong plugs ?
#3
That is a standard feature of Windows to have a 2nd or third monitor. As long as the graphics card have the outputs. I have room for 2 more HDMI out puts.
No the oval does not move.
both Tv's have HDMI and RGB and full audio and video RCA plugs
Pic of both TVs. Full screen on both.
Here's a pic of both TV's in computer mode and the menu to use both via Windows.
No the oval does not move.
both Tv's have HDMI and RGB and full audio and video RCA plugs
Pic of both TVs. Full screen on both.
Here's a pic of both TV's in computer mode and the menu to use both via Windows.

#4
If you exchange cables, does the oval go over to the other TV?
Also go through the menus in the TV setup and check the TV instructions to see if there is a "vignette" mode that intentionally produces that oval.
Also go through the menus in the TV setup and check the TV instructions to see if there is a "vignette" mode that intentionally produces that oval.
#6
Member
Yep, that's weird.
Best guess is that the HDMI+ethernet cable switches to a higher frequency when the signal goes to video. Could also be that the +ethernet functions are messing with the voltage/capacitance readings and causing problems with the Vizio TV.
1) What happens if you split-screen video and computer on monitor #2? Run video in less-than-full-screen?
2) Possible that new HDMI cable cause an update to the monitor #2 driver, try rolling back the driver.
3) Try setting monitor #2 to a different refresh rate / bit depth.
Best guess is that the HDMI+ethernet cable switches to a higher frequency when the signal goes to video. Could also be that the +ethernet functions are messing with the voltage/capacitance readings and causing problems with the Vizio TV.
1) What happens if you split-screen video and computer on monitor #2? Run video in less-than-full-screen?
2) Possible that new HDMI cable cause an update to the monitor #2 driver, try rolling back the driver.
3) Try setting monitor #2 to a different refresh rate / bit depth.
#7
OK, this is weird! I was going to try Hal's suggestion. I call up the display screen where I can make changes. Before I begin to make the changes I tune in on the 2nd screen with the live TV. All of a sudden the screen is full, no dark sections. Full screen, several different channels. I did not tough or change anything.
I think I need to put on my foil hat.
I think I need to put on my foil hat.
#8
Forum Topic Moderator
I think when you run TV full screen, it's likely sending the signal in either a different resolution and/or using some form of HDCP (copy protection). The monitor isn't handling it quite right.
It could be the quality of the cable isn't great, HDMI cables aren't always reliable over about 6'. It's entirely possible that a better quality cable (not necessarily more expensive) will eliminate your problem.
That's my theory at least.
It could be the quality of the cable isn't great, HDMI cables aren't always reliable over about 6'. It's entirely possible that a better quality cable (not necessarily more expensive) will eliminate your problem.
That's my theory at least.
#10
Member
Originally Posted by Norm201
OK, this is weird!