Possibly related issue.. I have a Galaxy Tab 4 (10.1) with a Nook case from Barns&Knoble. I thought at first I had the same problem as above. When I tried plugging in some computer speakers into the headphone jack it seemed I couldn't get any sound out. Tried above suggestions...nothing. Tried another computer speaker set..same thing...nothing. Ultimately I tried a standard 1/8" headphone jack from a set of ear-buds...it worked! After a little examination I realized that the silly plastic case (Nook case) that my Tab 4 was in had a smaller plastic hole for the plug to pass thru than what would normally be required to let the speaker plug seat completely in. This prevented the 3 point stereo connection...duh. So I drilled out the plastic hole on the Nook case, put the case back on, inserted plug..problem solved. Now all my slightly fatter 1/8" stereo plugs work fine.