I just sent it back to the vendor (under warranty) because the latest OS update caused the speakers to melt.
While browsing the net I noticed the smell of burnt plastic, and quickly noticed the edges (where the speakers are) was too hot to touch. Turned the thing off but they were cooked.
Then I found I wasn't alone... https://forums.geforce.com/default/topic/834884/shield-tablet/speakers-damaged-after-3-0-update/
Apparently somehow the speakers got fed DC current while doing nothing in particular. Impressive if you ask me.