Yamaha RX-V381 Owner's Manual page 71

Problem
No sound is coming from the subwoofer.
No sound from the playback device (connected to
the unit with HDMI).
No sound from the TV (when HDMI Control is
used).
When playing back DSD audio, the unit disables
the audio output from a TV.
Only the front speakers work on multichannel
audio.
Noise/hum is heard.
The sound is distorted.
Cause
The playback source does not contain Low Frequency Effect (LFE)
or low-frequency signals.
Subwoofer output is disabled.
The volume of the subwoofer is too low.
The subwoofer has been turned off by its auto-standby function.
The TV does not support HDCP (High-bandwidth Digital Content
Protection).
The unit is set not to output audio input through HDMI jacks from
the SPEAKERS terminals.
The number of devices connected to the HDMI OUT jack exceeds
the limit.
The TV is set to output audio from the TV speakers.
A TV that does not support ARC is connected to the unit only with
an HDMI cable.
(If the TV is connected to the unit with an audio cable)
The TV audio input setting does not match the actual connection.
(If you are trying to use ARC)
ARC is disabled on the unit or TV.
The unit does not support DSD audio output from a TV.
The playback device is set to output 2-channel audio (such as
PCM) only.
The unit is too close to another digital or radio frequency device.
The cable connecting the unit and playback device is defective.
The volume of the unit is too high.
A device connected to the unit's output jacks is not turned on.
Remedy
To check it, set "Extra Bass" in the "Setup" menu to "On", in order to output the
front channel low-frequency components from the subwoofer (p.55).
Perform YPAO (p.25) or set "Subwoofer" in the "Setup" menu to "Use" (p.54).
Adjust the volume on the subwoofer.
Disable the auto-standby function of the subwoofer or adjust its sensitivity level.
Refer to the instruction manuals for the TV and check the TV's specifications.
In "Audio Output" in the "Setup" menu, set "Amp" to "On" (p.57).
Disconnect some of the HDMI devices.
Change the audio output setting on your TV so that the TV audio is output from
the speakers connected to the unit.
Use a digital optical cable to make an audio connection (p.19).
Use "TV Audio Input" in the "Setup" menu to select the correct audio input jack
(p.57).
Set "ARC" in the "Setup" menu to "On" (p.58). Also, enable ARC on the TV.
Change the audio output setting on the playback device to PCM.
To check it, use "Signal Info." in the "Option" menu (p.49). If necessary, change
the digital audio output setting on the playback device.
Move the unit further away from the device.
If there is no problem with the connection, replace with another cable.
Turn down the volume. If "ECO Mode" in the "Setup" menu is set to "On", set it to
"Off" (p.61).
Turn on all devices connected to the unit's output jacks.
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