I have a strange problem with youtube. Videos that I could see before now I can hear only the sound. And this is happening since last week end. The funny thing is that videos with advertisements works good. I tried to run again the computer or also to restart my computer from a certain point in the past losing the latest updates and I thought I could work. It worked but only for one day.
As a temporary workaround, you can try one, or both, of the following:
1) Right click on the player > click Settings > Disable Hardware Acceleration > Refresh your Internet Browser
2) Try closing your browser and re-load the video.
I solved this by changed the balance option, on the playback devices>properties>levels>balance.
I use an extension from my headphone and it seems to just pass 1 channel.
Okay im not too sure if this is the problem but I hope it works for you as this happened to me.
Depending on which browser you have (I use Chrome) Go to the Settings which you will find under the menu button in the right hand corner of your browser (If you are using Chrome)
And then on the left hand side you will see a list of options:
History
Extensions
Settings
Help
You want to click the Extension button and a page will open up.
Once this have done this you should see "Flash Extension" Or "Adobe Flash somthing" Whatever it called.
Just click enable and refresh your browser and it should work!
For Firefox. Go to tools -> Options -> Click the advanced tab on the bottom left -> De-select Use hardware acceleration when available -> Refresh video and all should be well with the world.
I finally figured out what works for me, so if none of those work for you try this! I'm using chrome. Go to chrome settings from the menu and scroll down to where it says "Privacy". Then, uncheck the box that says "Protect you and your device from dangerous sites". I reloaded youtube and it worked fine after that.
I use an extension from my headphone and it seems to just pass 1 channel.