I recently fixed two of my 890 Pro remotes by doing this, and I thought I'd share some tips.
1. Remove the battery cover and unscrew the two phillips screws at the back:
2. This is the tricky part: prying open the remote. There are 8 big tabs along the sides and two small tabs at the top holding it together. The side tabs are very easy to break, and you will probably break at least one. You don't need all of them to have the remote feel tight so don't worry too much, but here's how to avoid that.
Find some kind of thin plastic object (like a tongue) that can fit in the crack between the top and bottom. If you care about the appearance of your remote make sure you use something made of soft plastic! Hard plastic or metal will fray the edge of your remote. I recommend to start at the second tab from the top, as you will not feel that area when holding the remote in case it does get chipped. You don't want to start with the topmost side tab since the top tabs are clamping the top together. So take your thin plastic tongue and jam it in there, pushing against the tab. At the same time, pry the remote open with your fingers and push the top to the side to try to unhook the tab in order to avoid breaking it. The top tab clamps over the bottom tab, so if you're trying to open a left tab, push the top half of the remote to the right while prying it open.
Once you have one tab open, work your way around the bottom of the remote, and finally pull away the top.
3. Remove the circuit board by unscrewing it. There are two screws in the middle attaching it to the bottom half of the remove cover.
4. Remove the power connector, use a small flat screwdriver to pull away the two sides of the connector.
5. Pull off the daughter board (on the 890 Pro).
5. Now you have access to the circuit board. Here you can do a couple of things like:
- Replace the LCD screen: On the back side of the board, unhook the LCD connector. Unhook the four small white tabs that attach the LCD to the board. Slice the connector cable through the hole to detach the LCD screen.
- Fix the tilt sensor: on one of my remotes the tilt sensor broke. The tilt sensor consists of a little metal ball encased in a cavity surrounded by four metal contacts. When the ball shorts two of the contacts the sensor is activated. On my remote, the top cover on the cavity opened up, the metal ball escaped and was rolling free inside the remote. I simply put the ball back in and snapped the sensor cover back on.
- Reattach or solder any other loose components, like the USB connector.
- Fix broken/missing buttons: you have access to the top half and you can remove the tape and screws to replace missing buttons or clean it up.