Logitech Premium USB Headset 350 automatically control the volume on Win 7. it seems that there something wrong with my sound card on headset, I tried to install the newest driver but it still not work. I cannot control the volume, the volume control automatically fall to the bottom. do you have any solutions for my case?

SOURCE: Logitech 350 Headset Casing

Had the same problem, no headphone speakers would work.
First use a flat head screwdriver and insert in between leather padding
and plastic case and pry apart. Best to start at one area, insert a wedge
and pry further along. It will take a bit of force before it pops apart.

Take out 4 small philips screws

I found that the wire had broke right at the entry grommet. I pulled the
wire through and wiggled it and the speakers went on and off.

In my case I felt it was best to redo all the wiring. I first took these pictures
to have a map and pulled through an extra 4" of wire through and cut/desoldered
the wires.
Here are the original wiring connections at the speaker
and what must be the common. This was the wire that was broken
inside.

I re-soldered all the connections and separated them as best I could with
electrical tape (no shrink). Put everything back together and so far
seems to work fine.

SOURCE: i can't hear anything from my logitech headset

Hi Itsyen, go to start menu, control panel, sound. Then here go into the Tabs and select the Headset as Mic and Speakers. Apply, Done !
Thanks and have a nice day Julien