Samsung TV & Audio QN65QN90CAFXZA 65" Class QN90C Neo QLED 4K Smart TV SCREEN DIM Error Fix: Screen Dims Randomly

Error code SCREEN DIM on the Samsung TV & Audio QN65QN90CAFXZA 65" Class QN90C Neo QLED 4K Smart TV means: Screen Dims Randomly. Screen brightness suddenly drops or dims on its own. Most commonly caused by Brightness Optimization / Eco Sensor: Settings → General → Power and Energy Saving → Brightness Optimization → Off. Also disable Ambient Light Detection and Motion Lighting. On OLED models, the Automatic Brightness Limiter (ABL) reduces brightness on large bright areas — this is normal OLED behavior. Check picture mode — "Movie" and "Filmmaker" modes are intentionally dimmer. If random dimming persists after disabling auto-brightness features, the LED backlight driver or power supply may be degrading.

The most successful fix is "Test and Replace LED Backlight Driver or Power Supply Board" (hard difficulty, ~90 minutes). Estimated DIY cost: $0-$20. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Test and Replace LED Backlight Driver or Power Supply Board") is rated hard difficulty and takes about 90 minutes. Tools needed: T10 Torx screwdriver, Phillips screwdriver, Multimeter, Anti-static wrist strap.

DIY cost: $0-$20. Professional repair typically costs $150-$300. Many homeowners save money by trying the top-ranked community fix first.

The Samsung TV & Audio QN65QN90CAFXZA 65" Class QN90C Neo QLED 4K Smart TV has 8 other known error codes, including: 2 BLINKS (Power Supply Board Fault), 5 BLINKS (LED Backlight / Driver Protection Shutdown), 6 BLINKS (Main Board / T-CON Communication Failure), ANYNET FAIL (Anynet+ (HDMI-CEC) Not Working), APP CRASH (App Freezes or Crashes), and 3 more.

Error code SCREEN DIM also appears on 4 other Samsung TV & Audio models: QN55LS03BAFXZA 55" Class The Frame QLED 4K Smart TV, QN65Q80CAFXZA 65" Class Q80C QLED 4K Smart TV, QN65S90CAFXZA 65" Class S90C OLED 4K Smart TV, UN55CU8000FXZA 55" Class CU8000 Crystal UHD 4K Smart TV. The fix may vary by model, so check each model's specific page for tailored repair steps.