I had a problem with this on my S6 Edge and got it replaced, the problem persisted then I got the S7 edge, it had the exact same problem so I got it replaced and now the replaced one is doing it too. If I'm listening to music outside while it is windy, the volume will go all the way down to zero. When I open up my phone whole this is happening, a blue box will appear around the app that is in the top left corner and that app will continuously open and act as if the screen is being pressed on the too left of the screen. I've had this problem with all four of my Galaxy S edge phones.
I had exactly the same problem with S3 and now S7 including blue box on app shortcut. I's definitely related to headphones/buds use. I use Etymotics buds which sound unbelievable but I suspect it has to do with usage of some buds/phones. I tried my buds in another Galaxy which never had the problem and when I started playing with the bud buttons the same Galaxy volume problem ocured. I cleaned my jack and plug and will see if that solves the problem on my S7. Maybe wireless buds are a good idea a la iPhone. What has Samsung to say about this???
Update: Seems to be an incompatibility concern with some buds. I tried factory Samsung buds that came with the S7 and they seem to work fine with full button control - pause, play, vulume up, volume down. Also tried a pair of Etymotics that doesn't have any button controls and they played well for a long while with no volume concerns. Looks like the Etymotics has a slight variation in the ring spacing on the plugs and that may be causing contact fluctuations. Will continue with other buds. Any other input would be helpful.
Update: I've tried numerous buds and it seems that it's a concern with the input jack connection, with differing plugs. Some buds have slightly different spacing and caused this problem repeatedly but not in any predictable or consistent manner. Others never gave any problems. My suggestion is that if the problem happens, reseat the plug into the headphone jack. There is no way to tell if it will happen again but it prevented continuous volume problems. Cleaning the jack and plug with a small needle to remove any dust, and contact spray to maintain better conductivity is a good preventative also. It's not very surprising that this type of small jack with several contacts and functions would cause this type of problem but it is very annoying. It may be a key reason that buds will increasingly become wireless.
So I guess Samsung tech support has no fix for this.....I am having the same issue. Volume goes up, then down, my gym membership app opens up like Im pressing it, and today I could not even shut my phone off after one reset.
I got the same problem yesterday. I have a S7 edge and use the earphones that I got with the phone. The sound quality goes bad, static noice, and the volume goes down to 0. The phone keeps tapping/clicking something.