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Vizio TV Screen Problems (Won’t Go Full Screen/Keeps Dimming)

Some Vizio TVs will experience problems when the TV does not display the image in full screen, or when the screen dims. This can be frustrating and annoying, taking away from the experience of watching a good TV show or playing fast-paced game. If you have been having similar issues, this article contains both causes and solutions to both of these issues.

A Vizio TV will not display full screen if the aspect ratio does not match that of the TV. This can be changed in the TV settings, or may need to be changed in your device’s settings. A dim screen is caused by either a hardware failure or by picture settings that automatically adjust the display.

Person sitting on sofa with legs up on table eating popcorn and watching movie

You will find more detail regarding these two issues in the sections below. You can also learn how to hard reset and factory reset the TV, two common troubleshooting methods that resolve most issues.

Vizio TV Not Showing Full Screen

White couple smiling and watching TV together

A Vizio TV that is not displaying in full screen will play the image with black bars around it. This makes the display look smaller and can be frustrating because the screen is not being used to its full potential.

A Vizio TV may not display full screen if the aspect ratio does not match that of the TV. This can be changed in the TV settings or may need to be changed in your device’s settings. You can change the Aspect Ratio settings on your TV by going to Menu > System > OK > Aspect Ratio > OK.

Reasons Why This is Happening

This is an issue with the aspect ratio of the display. Most commonly, older TV shows or movies that are played on a new wide-screen TV will have a smaller aspect ratio than their modern counterparts. The older TVs had an aspect ratio of 4:3, whereas most widescreen TVs have a ratio of 16:9.

For these older films, the TV will automatically fill in the gaps with black bands either side of the image, making the display appear smaller. This is the TV trying to fit the foreign aspect ratio in the best way for the viewer.

You may also experience black bands across the top and bottom of the screen. This occurs when the film was made using a panoramic feature. In this case, the TV is filling in the missing part of the display above and below.

The above examples are simply the TV adjusting the display to accommodate an unsuitable aspect ratio. However, sometimes you will notice movies will have various aspect ratios used for artistic effect. This usually will become obvious when the display begins expanding to fit the entire screen.

You may also have a device plugged into your TV that has a fixed ratio. This usually has to be changed on the device itself under the display settings.

This is a common issue with cable set-top boxes. If you cannot work out how to change the aspect ratio, you could also try resetting the cable box instead.

How to Get Full Screen on Vizio TV

Making the display full screen is easy. You can do this either using the remote, or through the TV’s display settings.

For the remote, simply press the ‘Aspect Ratio’ button, to cycle through each option. If you’re unsure which button this is, it looks like a little square.

If you cannot find this function on your remote, you should try the TV settings instead. These settings can be changed using the steps below.

Copyright protected content owner: and was initially posted on June 2, 2021.

Step 1: Press the ‘Menu’ button on the remote.

Step 2: Select ‘System’

Step 3: Select ‘Aspect Ratio’

Step 4: Cycle through each option until you are satisfied.

There are not many options to choose from. The image is usually automatically set to the ‘Normal’ option. This displays the image in its true ratio in the centre of the screen, using black/dead pixels to block out the unused space.

There is also a ‘Wide’ setting, which will stretch the image to fill the entire TV screen. This is often undesirable because it gives the display an unusual appearance. A 4:3 display will appear wider and a panoramic display will appear taller or thinner.

The final option is the ‘Zoom’ option, which will magnify the image to remove any unused areas on the screen. This results in some of the image being cut off. If there is only a small difference in the aspect ratio, this option will be fine. However, if you use this option with a 4:3 ratio and a widescreen TV, you will lose a significant amount of the image.

If the film is using different aspect ratios for artistic effect, you should keep this setting on ‘Normal’. You can search online to find out if this is the case for the content you are watching. One example of this is in Marvel’s ‘Wandavision’.

Vizio TV Keeps Dimming

Couple watching TV together on sofa

Why Does My Vizio TV Keep Dimming?

A Vizio TV will dim if you have enabled settings that automatically adjust the brightness of the display for a better user experience. When the TV senses that the display is too bright, it will dim the screen.

However, as with most automatic features, there are always users who prefer their display to remain fixed until they choose to manually change it. The features that will dim your display include the following. Keep in mind that your TV will only have one or a few of these settings.

· Backlight Control

· Auto Brightness Control

· Ambient Light Sensor

· Adaptive Luma

· Smart Dimming

· Zone Dimming

Another cause for dimming seems to be when the TV engages the HDR function. This is a HDMI-specific function that usually occurs when displaying 4K content. This will be consistent the whole time you are using 4K.

Unfortunately, there is also the possibility is that the LEDs in your TV screen are failing. This could be the entire screen, or just part of the screen. LEDs will either burnout or experience a driver circuit failure, both of which will affect your display.

How to Stop Vizio TV from Dimming

As you have probably guessed, you can easily prevent the constant dimming of the display by disabling the features listed above. Below is where each of these features can be found.

Backlight Control: Menu > Picture > More Picture > Backlight Control > Off

Auto Brightness Control: Menu > Picture > Auto Brightness Control > Off

Ambient Light Sensor: Menu > Picture > More Picture > Advanced Picture > Ambient Light Sensor > Off

Adaptive Luma: Menu > Picture > More Picture > Advanced Picture > Adaptive Luma > Off

The ‘Smart Dimming:’ and ‘Zone Dimming’ settings are not as common, only found in certain models. However, they will be located in a similar settings menu. You should be able to find the purpose of each function in your User’s Manual.

The ‘HDR’ function is found in a different area because it is related to the HDMI settings. These can be found in the pathway below.

Settings > Picture > Advanced Picture Settings > HDMI Function

You should then be able to turn ‘HDR’ off. Some people do not have any issue with this function regarding dimming issues; it depends on which device you are using and what you are using it for. You also may not have this function if you have an older Vizio TV.

For any issue relating to LED malfunction or circuit failure, you will need to contact a technician to look at the TV. Trying to fix this issue yourself is incredibly time consuming and will also void your warranty, if the TV is not very old. Unfortunately, this will require a repair or replacement of the screen, circuit board, or even the entire TV.

One thing you might like to try before you resort to this is a hard reset or factory reset. A hard reset will clear any errors in the TV, but will also retain your saved preferences and downloaded content. Follow the steps below to try this.

Step 1: Turn off the TV and unplug all devices.

Step 2: Unplug the TV from the wall.

Step 3: Press the ‘Power’ button on the TV for 30 seconds.

Step 4: Wait another 10 minutes before plugging the TV back in.

Step 5: Turn the TV back on and plug your devices back in, one at a time.

If you would like to try a factory reset, you will lose all your saved data. You can return your TV to its default settings by following the steps below.

Copyright article owner is for this article. This post was first published on June 2, 2021.

Step 1: Press the ‘Menu’ button on the remote.

Step 2: Navigate to System > Reset & Admin.

Step 3: Select ‘Reset TV to Factory Defaults’.

Step 4: Enter your TV code or the default code, ‘0000’.

Step 5: Select ‘Reset’ to confirm the factory reset.

Step 6: Wait for the TV to completely restart.

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Vizio TV Keeps Restarting

ReadyToDIY is the owner of this article. This post was published on June 2, 2021.

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