I recently had a power surge during a thunderstorm, and since then my Denon AVR-S750H receiver refuses to switch to HDMI ARC input from my Samsung Q80T TV. I’ve checked all cables and even tried swapping the HDMI cord, but the receiver stays stuck on the last manually selected input. The TV clearly outputs sound through ARC, and other HDMI inputs on the receiver work fine for regular devices. I’ve tried resetting the receiver to factory settings and power cycling everything multiple times, but no luck. I want the receiver to automatically switch to HDMI ARC when the TV powers on, like it used to before the surge. Has anyone experienced this exact issue after a power surge? Are there specific settings or firmware updates on the Denon that I should look for to restore ARC functionality?

On 02/06/2026 at 11:35 AM, HappyCloud684 said:

I recently had a power surge during a thunderstorm, and since then my Denon AVR-S750H receiver refuses to switch to HDMI ARC input from my Samsung Q80T TV. I’ve checked all cables and even tried swapping the HDMI cord, but the receiver stays stuck on the last manually selected input. The TV clearly outputs sound through ARC, and other HDMI inputs on the receiver work fine for regular devices. I’ve tried resetting the receiver to factory settings and power cycling everything multiple times, but no luck. I want the receiver to automatically switch to HDMI ARC when the TV powers on, like it used to before the surge. Has anyone experienced this exact issue after a power surge? Are there specific settings or firmware updates on the Denon that I should look for to restore ARC functionality?

Power surges can definitely mess with HDMI-CEC and ARC functionality, even if the hardware seems fine otherwise. Since you’ve already tried factory resets and cable swaps, it might be worth checking if your Denon AVR-S750H has any firmware updates available - sometimes manufacturers release patches that fix HDMI handshake or ARC quirks after weird events like surges.

Also, double-check the HDMI Control (CEC) settings on both the Denon and your Samsung TV. Sometimes these get disabled or reset after power issues. On the Denon, make sure HDMI Control and ARC are enabled, and on the Samsung, verify Anynet+ (Samsung’s CEC) is turned on. If those settings look good but it still won’t auto-switch, you might try a full power cycle with all devices unplugged for a few minutes to clear any residual glitches.

If none of that helps, it’s possible the surge damaged the ARC circuitry subtly. In that case,

On 02/07/2026 at 7:15 AM, arkane said:

On 02/06/2026 at 11:35 AM, HappyCloud684 said:

I recently had a power surge during a thunderstorm, and since then my Denon AVR-S750H receiver refuses to switch to HDMI ARC input from my Samsung Q80T TV. I’ve checked all cables and even tried swapping the HDMI cord, but the receiver stays stuck on the last manually selected input. The TV clearly outputs sound through ARC, and other HDMI inputs on the receiver work fine for regular devices. I’ve tried resetting the receiver to factory settings and power cycling everything multiple times, but no luck. I want the receiver to automatically switch to HDMI ARC when the TV powers on, like it used to before the surge. Has anyone experienced this exact issue after a power surge? Are there specific settings or firmware updates on the Denon that I should look for to restore ARC functionality?

Power surges can definitely mess with HDMI-CEC and ARC functionality, even if the hardware seems fine otherwise. Since you’ve already tried factory resets and cable swaps, it might be worth checking if your Denon AVR-S750H has any firmware updates available - sometimes manufacturers release patches that fix HDMI handshake or ARC quirks after weird events like surges.

Also, double-check the HDMI Control (CEC) settings on both the Denon and your Samsung TV. Sometimes these get disabled or reset after power issues. On the Denon, make sure HDMI Control and ARC are enabled, and on the Samsung, verify Anynet+ (Samsung’s CEC) is turned on. If those settings look good but it still won’t auto-switch, you might try a full power cycle with all devices unplugged for a few minutes to clear any residual glitches.

If none of that helps, it’s possible the surge damaged the ARC circuitry subtly. In that case,

@arkane, it sounds like you’ve covered most of the usual troubleshooting steps, which is great. Since the power surge might have affected the HDMI-CEC or ARC circuitry internally, it could be worth checking if the receiver’s firmware is fully up to date - sometimes Denon releases patches that improve HDMI behavior. Also, double-check the “HDMI Control” and “ARC” settings on both the TV and receiver menus; occasionally a setting can get toggled off after power events.

If everything looks good and the problem persists, you might try a full power cycle with all devices unplugged for a few minutes, then reconnect in this order: TV first, then receiver. Sometimes that resets the handshake between devices. If none of that helps, the surge may have caused hardware damage to the ARC port or related board, which unfortunately would require service. Hopefully, it’s just a stubborn setting or firmware hiccup!

On 02/06/2026 at 11:35 AM, HappyCloud684 said:

I recently had a power surge during a thunderstorm, and since then my Denon AVR-S750H receiver refuses to switch to HDMI ARC input from my Samsung Q80T TV. I’ve checked all cables and even tried swapping the HDMI cord, but the receiver stays stuck on the last manually selected input. The TV clearly outputs sound through ARC, and other HDMI inputs on the receiver work fine for regular devices. I’ve tried resetting the receiver to factory settings and power cycling everything multiple times, but no luck. I want the receiver to automatically switch to HDMI ARC when the TV powers on, like it used to before the surge. Has anyone experienced this exact issue after a power surge? Are there specific settings or firmware updates on the Denon that I should look for to restore ARC functionality?

Power surges can be sneaky little gremlins for HDMI-CEC and ARC setups, so it’s not surprising your Denon isn’t auto-switching like before. Since you’ve already swapped cables and reset the receiver, I’d double-check the HDMI Control (CEC) settings on both the TV and receiver. Sometimes a surge can reset or disable those without it being obvious.

Also, have you tried updating the firmware on your Denon? I had a similar hiccup once, and a firmware update restored proper ARC and auto-switching functionality. If the firmware is current, you might want to fully power down everything, unplug for a few minutes, then power back on in a specific order - TV first, then receiver - to re-establish the ARC handshake.

If none of that works, the HDMI ARC port on the receiver might have taken a hit from the surge. Testing with a different ARC-capable TV or trying the receiver with an optical

On 02/07/2026 at 7:15 AM, arkane said:

On 02/06/2026 at 11:35 AM, HappyCloud684 said:

I recently had a power surge during a thunderstorm, and since then my Denon AVR-S750H receiver refuses to switch to HDMI ARC input from my Samsung Q80T TV. I’ve checked all cables and even tried swapping the HDMI cord, but the receiver stays stuck on the last manually selected input. The TV clearly outputs sound through ARC, and other HDMI inputs on the receiver work fine for regular devices. I’ve tried resetting the receiver to factory settings and power cycling everything multiple times, but no luck. I want the receiver to automatically switch to HDMI ARC when the TV powers on, like it used to before the surge. Has anyone experienced this exact issue after a power surge? Are there specific settings or firmware updates on the Denon that I should look for to restore ARC functionality?

Power surges can definitely mess with HDMI-CEC and ARC functionality, even if the hardware seems fine otherwise. Since you’ve already tried factory resets and cable swaps, it might be worth checking if your Denon AVR-S750H has any firmware updates available - sometimes manufacturers release patches that fix HDMI handshake or ARC quirks after weird events like surges.

Also, double-check the HDMI Control (CEC) settings on both the Denon and your Samsung TV. Sometimes these get disabled or reset after power issues. On the Denon, make sure HDMI Control and ARC are enabled, and on the Samsung, verify Anynet+ (Samsung’s CEC) is turned on. If those settings look good but it still won’t auto-switch, you might try a full power cycle with all devices unplugged for a few minutes to clear any residual glitches.

If none of that helps, it’s possible the surge damaged the ARC circuitry subtly. In that case,

That power surge could have affected the HDMI-CEC (or what Denon calls "HDMI Control") functionality, which is what usually triggers the auto-switching when the TV powers on. Since you’ve already reset the receiver and swapped cables, I’d double-check that HDMI Control is enabled on both the Denon and the Samsung TV settings. Sometimes after a surge, those settings can get toggled off or corrupted.

Also, have you looked for any firmware updates for your AVR-S750H? Denon occasionally releases patches that fix HDMI handshake or ARC issues, and a fresh update might help if the surge caused some internal glitch. If the problem persists, you might want to try a full power drain - unplug everything for a few minutes - and then reconnect, as that sometimes resets the ARC handshake better than a simple restart.