I used a heat gun, too. I was worried after reading comments that it would burn up the LCD, so I heated it a little bit at a time, rotating it like you did, and checking to see if I could get my knife under it. I must have hit one of the buttons because it did turn on, but that did reassure me that the display was okay.

It's open. Now that the watch and I have had a few minutes to cool down, I'm ready for the next step. Not as difficult as I thought it could be. Tomorrow, I'll be replacing the battery in an iPod Touch 6th Gen.

Okay, I found it.

After removing the mechanism, I turned it on and noticed that it only worked if I pushed the motor towards the battery. Once I removed the spring I noticed that one of the two metal strips connecting the motor to the board was split right where there is a slight bend. I applied a little bit of solder to repair the connection and it is working again.

I have the same issue. It worked fine a few times and then quit. The display works fine, too.

I accidentally started it while taking it apart. When I was loosening the base, it started to work again. There's something applying enough pressure to the mechanism to stop it whenever it is pushed into the handle.

With the base re-installed, the toothbrush stops again. It works whenever I push the assembly down. I'm suspecting that the blue ring at the top may have something to do with it.

I found that I had to turn it counter-clockwise. It only tightened when I turned it clockwise.

Instructions for replacing the seal are here: iPhone Display Adhesive Replacement

I just had the same experience. The blue backing would not separate from the adhesive.

I tried a new tactic: Remove the ping backing and apply to the case, and then remove the blue backing. No go. It stuck to the blue backing more than it did to the case.

I should have just left the remains of the old strips in place. Instead, I just installed the battery without the adhesive. I hope that’s good enough.