theangelboy
500+ Head-Fier
While I haven't tried this on stuck set, physics says that you should be able to tell if it's stuck by shining a bright flashlight through the grille side and looking at the color pattern shining through on the pad side (all the pictures I have seen the membrane is stuck to the outside magnets). Here is the full post I made about it. https://www.head-fi.org/threads/hifiman-he6-se.886229/post-16685778How can I tell whether a driver is stuck without opening the backplate? I'm picking up a pair from a local seller, and I don't think he would be happy to have his headphones opened up before money changes hands.
EDIT: I see some fixed it by "reverse CPR". Good to know.
Let us know how it goes!