I have a 2010 SR5, my radio unit is the non-navigation and I believe it's Part Number: 86120-35370.
I was experiencing the same issues when it was very cold out and now today my sound output just went dead. I can see the stereo is playing a CD, FM, or AUX but no sound comes out of the speakers. I was able to verify the speakers are still working using the phone bluetooth unit.
***Side note** not sure if it's related but the aftermarket remote starter that came with the car stopped working a few months ago. I never bothered to fix it.
Has anyone else had this issue with the stock stereo? Any recommendations on where to start looking? I have very little car electronics knowledge but would prefer to get through the basic troubleshooting before paying someone.
Thanks!