2. Maintenance
The screws for the hinges sometimes becomes 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.
Apply lubrication on these spots on the photo. This will help with fluid open/close action and may reduce the crackling noise.
