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!