Yamaha RX-V793 flashing light on volume control and no volume

Per Yamaha support page: The volume light on my Yamaha AV receiver is flashing, what does this mean ? The "MUTE" function on your remote control has been activated. The reason that you can still hear a very low sound is that the muting circuit within your stereo is not a full mute, but rather a -20dB mute. To deactivate the "MUTE" function, simply press the "MUTE" button on your remote control. (Make sure the volume control is turned down to avoid damage to your system.) If you misplace or lose your remote control, you will have to purchase a new remote control unit, as there is no duplicate function on the front panel of your stereo. Unplugging the stereo will not deactivate the muting circuit, as the microprocessor "remembers" if the muting circuit was active prior to being turned off or unplugged. If you need to purchase a remote control, you may order one directly from our parts office. You may reach them by dialing (714) 522-9888 from 8 am to 3 p.m. Pacific Time, Monday through Friday. If you have any other questions, please contact our customer service department by dialing (800) 292-2982 Monday through Friday from 8:00 a.m. to 4:00 p.m.

There is a way to bypass the remote control if it is missing or defective. Enter Diagnostic mode by turning the receiver on while holding DVD/LD + preset button number 8.

Once in diagnostic mode, press preset button 7. twice to get to factory preset option. (Assuming you are fine with this of course).

Then turn the receiver off and on again,

Done :)