2. Maintenance
These black screws for the hinges sometimes become quite loose. You may want to apply some thread locker to them.
HOWEVER, the plastic of these screw holes tend to become very brittle and disintegrate. Try not to overly stress them when turning the screws. Never over tighten the screws.
I've designed a fix for the bottom half of the hinge screw holes in case they failed. I'll design one for the top if I happen to run into a unit with that kind of failure. I've heard it's quite common...
Apply a small amount of lubrication on these spots on the photo. This will help with fluid open/close action and may reduce the crackling noise.
