Eliminating Samsung Q90T from Shutting Down During HDR Playback

Samsung TVs in recent years have pushed the boundaries of picture quality with high‑dynamic‑range (HDR) technology, delivering deeper blacks, brighter highlights, and a broader color palette. The Samsung Q90T, launched in 2019, remains a favorite for home cinema enthusiasts, thanks to its quantum dot panel, 4K resolution, and immersive Dolby Vision support. However, some users report a frustrating issue: the TV shuts down unexpectedly during HDR playback. This article explains why the Q90T may power off while streaming HDR content and provides a comprehensive, step‑by‑step guide to resolving the problem.

Why Does the Q90T Shut Down During HDR Playback?

1. Power‑Management Firmware and Over‑Temperature Protection

Samsung’s Q90T incorporates a sophisticated power‑management system that monitors temperature, input load, and power draw. HDR content typically demands more processing power from the picture engine and, in some cases, more input‑to‑output signal bandwidth. If the internal temperature rises above a safe threshold, the firmware may trigger a shutdown to protect hardware components.

2. HDMI Handshake and HDR Metadata Errors

When a device sends HDR metadata through HDMI, the TV must perform a handshake to confirm compatibility. Faulty HDMI cables, mismatched HDMI version support, or incorrect HDR settings on the source device can cause the handshake to fail. In some firmware iterations, a failed handshake is treated as a critical error, prompting an immediate power‑off.

3. Firmware Bugs in HDR Processing Modules

Certain firmware releases contain bugs that affect HDR10+ and Dolby Vision decoding. If the decoding engine receives malformed metadata, it may crash, causing the entire picture subsystem to reboot or shut down.

4. Automatic Power‑Off and Energy‑Saving Features

The Q90T includes a “Power Off on No Input” feature that can be triggered by the TV’s internal logic if it believes no active source is present. HDR playback from a streaming device that briefly disconnects or misreports its status can inadvertently activate this feature.

5. HDMI‑CEC Interaction with External Devices

When HDMI‑CEC (Consumer Electronics Control) is enabled, the TV may receive “power off” commands from a connected device, especially if that device’s firmware misbehaves during HDR playback.

Initial Symptoms and What to Look For

• The TV powers off within 30–60 seconds of starting HDR playback.
• The screen remains black and the power LED stays lit until a reset is required.
• The TV may reboot automatically or require a button press to turn on again.
• The issue is reproducible with specific HDR content (e.g., streaming, Blu‑ray, or game console).
• The problem does not occur with SDR (standard dynamic range) playback.

If you observe these symptoms, proceed with the troubleshooting steps below.

Step‑by‑Step Troubleshooting Guide

A. Verify and Update Firmware

1. Check Current Firmware Version

   • Press the Home button.
   • Navigate to Settings → Support → Software Update → Software Update.
   • Note the version number.

2. Download Latest Firmware

   • If an update is available, choose Download.
   • Wait for the download and installation to complete.

3. Reboot the TV

   • After the update, restart the TV by turning it off, waiting 30 seconds, and turning it on again.

Firmware updates often contain critical bug fixes for HDR handling.

B. Disable HDR to Isolate the Problem

1. Navigate to Picture Settings

   • Press Home → Settings → Picture.

2. Turn Off HDR

   • Select Advanced Settings → HDR Settings → set HDR Mode to Off.

3. Test Playback

   • Play the same HDR content.
   • If the TV no longer shuts down, the issue is tied to HDR processing.

Re‑enable HDR after confirming the problem is resolved.

C. Adjust Picture Mode and HDR Settings

1. Select a Standard Picture Mode

   • From Picture, choose Standard or Movie instead of Dynamic or Game.

2. Disable Auto Brightness

   • Advanced Settings → Auto Brightness → set to Off.

3. Configure HDR10+ / Dolby Vision Settings

   • HDR10+ Settings → set HDR10+ Level to Off (if available).
   • Dolby Vision Settings → set Dolby Vision to Off.

4. Reset Picture Settings

   • If problems persist, use Picture → Picture Reset to return to factory defaults.

D. Inspect HDMI Connections

1. Check HDMI Cable Quality

   • Ensure the cable supports HDMI 2.0 or higher.
   • Replace any old or inexpensive cables.

2. Switch HDMI Ports

   • Move the source device to a different HDMI port.
   • Some ports handle HDR traffic better than others.

3. Confirm Source HDMI Version

   • Verify that the source device (Blu‑ray player, console, streaming stick) supports the same HDMI version as the TV.

4. Test Without HDR Source

   • Connect a non‑HDR source (e.g., a 1080p HDMI input).
   • If the TV stays on, the cable or port is likely fine.

E. Disable HDMI‑CEC

1. Open Settings → General → External Device Manager → Anynet+ (HDMI‑CEC)
2. Turn Off Anynet+
3. Reboot TV
4. Test HDR Playback Again

Disabling HDMI‑CEC prevents external devices from sending accidental power‑off commands.

F. Adjust Power‑Saving Settings

1. Navigate to Settings → General → Eco Solution
2. Set Power Off on No Input to Off
3. Set Power Saving to Off
4. Reboot the TV

These changes prevent the TV from interpreting input inactivity or power‑saving mode as a shutdown trigger.

G. Test with a Different HDR Source

• If you have multiple devices (e.g., a streaming stick, game console, Blu‑ray player), try each one individually.
• If the shutdown occurs only with one device, the issue may be on the source rather than the TV.

H. Use Samsung SmartThings Diagnostics

1. Install Samsung SmartThings on your smartphone.
2. Add the Q90T to the App.
3. Run a Diagnostic Test.
4. Review Any Error Codes and follow the suggested actions.

SmartThings can reveal hidden firmware bugs or hardware issues.

I. Reset the TV to Factory Settings

If all else fails, perform a full reset:

1. Settings → General → Reset
2. Enter Your PIN (default is 0000).
3. Confirm the Reset.

After resetting, reinstall any necessary apps and update firmware again.

Advanced Workarounds

1. Manual HDR Metadata Adjustment

If you are comfortable with the TV’s advanced menu:

• Navigate to Picture → Advanced Settings → HDR Settings → HDR10+ Level.
• Choose Low or Medium instead of Auto.
• This limits the HDR metadata processing load.

2. Re‑Pair HDMI‑CEC Devices

Sometimes the TV’s CEC database can become corrupted.

• Settings → General → External Device Manager → Anynet+ (HDMI‑CEC) → CEC List.
• Delete All Devices.
• Reconnect the devices one by one.

3. Disable “Auto Power Off” in External Device Manager

1. Settings → General → External Device Manager.
2. Select Auto Power Off and turn it Off.

This stops the TV from automatically turning off if it perceives a source as inactive.

4. Check for Over‑Temperature Symptoms

• Feel the back panel.
• If it feels unusually hot, give the TV a break before using it again.
• Ensure the room temperature stays below 30 °C (86 °F) and that ventilation is adequate.

When to Contact Samsung Support

• The issue persists after firmware update, resetting, and all settings adjustments.
• Error codes appear that are not documented in the manual.
• The TV physically overheats during normal operation.

Samsung support can schedule a technician visit or arrange a replacement if a hardware fault is identified.

Recap of Key Actions

• Update firmware to the latest version.
• Disable HDR temporarily to isolate the problem.
• Adjust picture mode and turn off auto brightness.
• Use a high‑quality HDMI cable and switch ports if needed.
• Disable HDMI‑CEC to prevent external power commands.
• Turn off power‑saving features that might misinterpret input inactivity.
• Reset to factory settings if all else fails.

By following these steps systematically, most users will stop experiencing unexpected shutdowns during HDR playback on the Samsung Q90T.

Final Thoughts

HDR offers a cinematic experience that many modern televisions, including the Samsung Q90T, deliver with remarkable fidelity. However, the increased processing demands can expose firmware or hardware quirks that lead to shutdowns. The key to resolving this issue lies in methodically testing each potential cause—from firmware and HDMI connections to power‑saving settings and external device interactions.

When troubleshooting, keep a detailed record of every change made and the result observed. This not only helps in isolating the root cause but also provides useful information if you need to involve Samsung support.

With the steps outlined above, you should be able to keep your Q90T running smoothly during all HDR content, allowing you to enjoy every frame of your favorite movies, shows, and games without interruption.