Yamaha RX-V757 No Left Channel Output - Video Sources Only

that would depend on the channel.
I've seen people complaining that one channel was blown while operating in 5.1 mode, but then in 6.1 suddenly and magically worked...it was just a speaker connected to the wrong output on the avr... start with checking that.
if that is not the issue, than it is possible that the input in just stereo and the output for the dsp is not set to copy stereo to all channels...but this should be noticeable in more speakers...rather all except left and right frontals.

Check the speaker of the left channel first. If found OK, check and replace damaged component/s at its audio output [Left] channel. Refer its circuit diagram. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Search the site by type in the brand name to your device, in the "Search box at the top right of the display window".

Short circuited component/s at its audio output stage circuit. Contact any service technician to get it repaired. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

The output transistor is probally shot,

Unfortunatly there is not any firmware to upgrade your unit to a higher HDMI format. There is a firmware though that corrects the following symptoms.

1. In case of playback of some DTS-HD Master Audio stream, pop noise may be generated.
2. Test tone may not be output under specific YPAO condition.
3. When test tone is output from presence channel, surround R channel is simultaneously output when speaker settings are PRESENCE SP "EXIST" and SWFR "NONE".
4. Multi channel input setting will be reset after power off the unit, in case of setting "INPUT CH" to "8CH" and "FRONT" to "VCR" or "V-AUX".

With what signal did you try? Maybe your signal source (DVD/TV or radio) didn't contain any sounds for the center channel.
Go to the Setup menu, Speaker setup / Manual setup and find there item called "Test tone". It will output a test tone to each speaker individually (you will see on LCD which speaker is being tested at each moment). If you will hear a sound from the center now, there is no issue and center is working fine, just your source didn't contain any sound for the center.

If it doesn't work, then either you have faulty cable, faulty speaker or faulty center output of the receiver.
- Try connecting the center speaker to different output of receiver (this will test if speaker is OK).
- Try connecting working LEFT speaker to left output with CENTER cable (this will test if cable is OK).
- Try connecting working LEFT speaker with working cable to the CENTER output (this will test the output of receiver if OK - but use the Test Tone from Setup).

Yes, sounds like your DSP chip has an issue. Not an inexpensive repair if that's the culpret. Around 400-500 to replace the chip. It's an awesome receiver and worth 300-400 in repair, however, a 3800 or 1800 can be had for 600-800 depending where you look. If you need more help, post a comment and I can help you some more.

Get into the cable box menu and look for audio settings, chances are your digital output from the cable box is off. If you still can't get audio, reply with your Cable Box Make & Model and I can help you further. Hope this helps

The right or left (side) output channel has blown out. If it uses discrete transistors you'll have to replace two of them (one PNP and one NPN) along with several resistors that are part of the circuit (I'm guessing the static occurs on any input source).
Now , if the static happens only on certain input, then the problem should not be in your amp.

This could be as simple as having input and output line audio reversed. Please check all sources for proper connection. You can do this at the receiver too, but not both receiver and sources.....accordianman