Sony master volume - Sony STR-DB870 Receiver

Dirty contacts on the buttons. Take apart and use electrical switch cleaner.

most hard resets for cellphones are done by done by powering off the device ,when fully off hold the power button, and volume up key at the same time until you see the android logo appear,but in other cases you can preform a hard reset by holding the power button ,home button and volume up key..please note that all personal data and downloaded apps will be erased

are you sure you have connected a sound source to the inputs correctly and turned on the sound source so it is playing into the sony?
If you have use the sony controls to turn up the volume and then select each input source one by one, do you then hear it?

Did mine years back - need to find part RV1802 1-418-773-11 ENCODER, ROTARY (MASTER VOLUME)
Volume went up and down turning in one direction. About 2 hour job, pull both knobs off, remove cover and front plate to get to volume switch assembly, replacement part requires desoldering and solder on new part.

For Vista/windows 7
Check with volume settings.

?· Right click on the speaker icon in taskbar and select volume control options.

?· Put a check mark on "All devices currently playing sound".

?· Make sure you have "The default communication device unchecked".

?· Place a check mark on both speakers and headphones.

For Windows XP

- Speakers, Headphones

?· In "Control Panel", select "Switch to Classic View", and open "Sounds and Audio Devices".

?· In "Sounds and Audio Devices Properties", click the "Audio" tab, and click the "Volume" of "Sound playback".

?· On the "Master Volume" screen, click "Properties" in the "Options" menu.

?· Add a check mark to "Playback" of "Adjust volume for" on the "Properties" screen, and check marks to "Master Volume" and "Wave" for the control to be displayed, and click the "OK" button.

?· On the "Master Volume" screen, remove the check marks from "Mute all" of "Master Volume" and "Mute" of "Wave".
Note: The settings may differ depending on the PC you are using. Please check items such as sound in the manual for the PC you are using.

this s bcoz of volume settings while calling i guess...u better check the volume settings friend!!!

Sony's web site has very thorough driver support. Log onto sony.com and download & install the latest audio driver for your system.

take the phone to amobile service center and have them fix it for you.

Set your SAT receiver to full volume and use your Sony TV volume control as the master volume control. If you use an external surround sound amplifier do the same thing using the amplifiers volume control as the master volume control.

Consider that all source devices that have the ability to control their output volume will output what they call line level 0dB when the source device is set for maximum volume. If you set the source device to 1/4 volume your output to the amplifier may be around -25dB or lower. Introduce that low of an audio level to the amp and you will have to turn the amp up to half way or better causing the amp to amplify noise too.