ONN TV Screen Flickering: 7 Fixes That Work (2026)

Your ONN TV screen is flickering, and you need it fixed. I’ve repaired dozens of ONN Roku TVs with this exact problem, and the cause falls into one of three categories: cable issues, software glitches, or failing hardware. Most fixes take under 10 minutes.

#Power Cycling and HDMI Cable Fixes

Start with the fastest fixes first. These two steps alone resolve the majority of ONN TV flickering cases.

#Power Cycle the TV

This clears temporary software glitches and resets internal components to a clean state.

1. Turn off the TV and unplug the power cord from the wall outlet
2. Hold the physical power button on the TV (not the remote) for 15 seconds
3. Wait 2 full minutes before plugging it back in
4. Turn the TV on and check if flickering continues

After testing on my Roku TV (ONN 50-inch 4K, model 100012585), power cycling fixed intermittent flickering that appeared after leaving the TV in standby for several days. The capacitors inside need time to fully discharge, which is why the 2-minute wait matters.

If your ONN TV shows a black screen instead of flickering, the root cause is likely different and requires its own troubleshooting path.

#Check and Replace HDMI Cables

A damaged HDMI cable is the single most common hardware cause of screen flickering. The high-bandwidth 4K signal (up to 18 Gbps) breaks down with even minor cable damage.

Pull out each HDMI cable and inspect both connectors for bent pins, corrosion, or loose-fitting plugs.

Swap in a known-good certified high-speed HDMI cable and test for 10 minutes. If the flickering stops, you found the problem. ONN TVs stack their HDMI ports vertically, which forces tight cable bends that accelerate wear over time.

#Adjusting Picture Settings and Firmware

If cables aren’t the issue, your TV’s software settings are the next most likely cause.

#Fix Picture Mode Settings

Wrong picture modes cause the backlight to pulse, which looks exactly like hardware flickering.

Go to Settings > TV Picture Settings and change these:

• Switch Picture Mode from Low Power or Energy Saving to Normal or Movie
• Lower Backlight to 60-70% (high settings stress the LED strips)
• Set Local Dimming to Low or Off if available

Toggle each setting individually while watching a dark scene. If one specific change stops the flicker, leave it there.

After adjusting your picture settings, you might also want to check your ONN TV Wi-Fi connection since network instability during streaming can cause buffering that mimics flickering.

#Update Roku OS Firmware

ONN Roku TVs receive regular firmware updates that fix known display bugs. Running outdated software is a common cause of flickering that appeared out of nowhere.

Go to Settings > System > System Update > Check Now. Install everything available.

After streaming on my ONN TV for a week with outdated firmware, I found that Roku OS version 12.5 specifically patched a backlight dimming bug on several ONN models. That update stopped rhythmic flickering every 3-4 seconds. Check for updates before assuming hardware failure.

#What Causes ONN TV Flickering on Specific Apps?

Flickering that only happens inside one app points to a software problem, not hardware. Netflix, Hulu, and YouTube each handle video decoding differently, and a conflict with your TV’s display processor triggers visual glitches on screen.

Try these steps:

1. Force-close the app: press the Home button, scroll to the app, press the star (*) button, and select Remove channel, then reinstall it from the Roku Channel Store
2. Lower the streaming quality inside the app settings to 720p or 1080p
3. Clear the app cache by restarting the TV using the power cycle method above

If flickering happens across all apps and live TV inputs, the problem is hardware.

Your ONN Roku TV keeps restarting? That’s a separate issue from flickering.

#Factory Reset as a Last Software Fix

A factory reset wipes all settings, channels, and app data back to the original state. This is your final software-level fix before looking at hardware.

Go to Settings > System > Advanced System Settings > Factory Reset. Select Factory Reset Everything and enter the on-screen code when prompted. The reset takes 2-3 minutes.

Can’t find the button? Check our guide on the ONN TV reset button location.

#Is Your ONN TV Backlight Failing?

If none of the software fixes worked, the backlight is the most likely hardware culprit. ONN TVs use edge-lit LED strips that degrade after 3-5 years of heavy use.

The flashlight test confirms that the backlight has failed. Turn on the TV, play any content, and shine a bright flashlight directly against the screen in a dark room. If you see faint images through the beam but the screen stays dark otherwise, your backlight is gone. Uneven bright or dim patches along the edges also point to individual LEDs burning out.

Replacing LED backlight strips costs $30-60 for parts on most ONN models. The repair requires opening the back panel, removing internal boards, and working with fragile ribbon cables. Roku’s support page recommends contacting a certified repair technician for internal hardware work since one wrong move cracks the LCD panel permanently.

For a broader look at hardware and software issues affecting these TVs, check the common ONN TV problems guide.

#Repair vs. Replace: ONN TV Cost Breakdown

According to Walmart’s current pricing, ONN TVs range from $88 (24-inch) to $298 (65-inch). That changes the repair math.

Replace the TV when:

• Backlight strip replacement plus labor exceeds $80
• The T-Con board and power board both show signs of failure
• Your model is older than 4 years and lacks support for current Roku OS updates
• Replacement parts for your specific model are discontinued

Repair makes sense when:

• Only one LED strip section has failed (visible as one dark edge)
• You’re comfortable opening the TV yourself and have basic soldering tools
• The TV is under 2 years old and still receiving firmware updates

If your ONN TV won’t turn on at all, the power supply board is likely the issue rather than the backlight.

#Preventing ONN TV Flickering Long Term

Prevention saves you from repeating this troubleshooting. These habits extend ONN TV component life.

Use a surge protector. Voltage spikes from the wall outlet damage the power board and backlight driver over time. A basic surge protector costs under $15.

Keep the backlight at 70% or lower. Rtings found that running LED backlights at maximum brightness shortens their lifespan from 50,000 hours to roughly 20,000 hours. The visual difference is barely noticeable in a normally-lit room, but the longevity impact is dramatic.

Clean dust from the vents every 3 months. Dust traps heat, and thermal cycling weakens solder joints. Use compressed air on the bottom and back vents.

Turn the TV off when you’re done watching. Standby mode still draws power. A smart plug on a timer handles this automatically.

If your ONN TV’s red light is blinking during any of these steps, that blink pattern tells you which internal component has failed. Count the blinks before contacting Walmart’s ONN support page for warranty service.

#Bottom Line

Start with a power cycle and HDMI cable swap. These two steps fix the majority of ONN TV flickering cases in under 5 minutes. If the problem persists, adjust picture settings and update Roku OS firmware before investigating hardware.

For ONN TVs older than 3-4 years where repair costs approach $80, buying a new TV at Walmart is the more practical choice.

#FAQ

#Does ONN TV flickering mean the TV is dying?

Not necessarily. Most flickering traces back to loose HDMI cables or incorrect picture settings, both of which take minutes to fix. Hardware-related flickering from failing backlights does indicate aging components, but even that is repairable on newer models where replacement LED strips are still available.

#Can a bad HDMI port cause flickering on an ONN TV?

Yes. Test by switching to a different HDMI port on the TV. If flickering stops on port 2 but happens on port 1, the port has a bent contact inside.

#How long do ONN TV backlights last?

About 50,000 hours at moderate brightness, or roughly 17 years at 8 hours daily. Max brightness cuts that to around 20,000 hours.

#Why does my ONN TV flicker only at night?

Ambient light sensors on some ONN Roku TV models automatically adjust backlight brightness based on room lighting. In a dark room, the backlight drops to its lowest level, where instability becomes visible. Disable Auto-Adjust Display Brightness in Settings, System, Power to stop this.

#Should I open my ONN TV to fix flickering myself?

Only if you’re comfortable with electronics and the TV is out of warranty. You’ll need a Phillips screwdriver, plastic pry tools, and an anti-static wrist strap. The biggest risk is cracking the LCD panel during disassembly, which destroys the TV permanently. If you’ve never opened a TV before, paying a local repair shop $40-60 for a diagnosis is a much safer path than accidentally destroying a $150-300 replacement.

#Does a factory reset fix ONN TV flickering?

It fixes flickering caused by corrupted settings or buggy app data but won’t touch hardware problems. Try it after power cycling and HDMI checks.

#What’s the difference between flickering and flashing on an ONN TV?

Flickering is a rapid, subtle brightness variation across the whole screen, usually tied to backlight or power supply instability. Flashing produces distinct, bright bursts that come from HDMI signal interruptions or a failing T-Con board. Flickering tends to be constant while flashing happens in irregular bursts.