I've posted this on the Nintendo forum, but I'll post it here since many of us aren't on there.
Now that we are aware that many people have had the cracked hinge on their DS Lite, I may have a really good theory about this.
The crack results from closing the DS Lite from an open, "LOCKED" position.
When the DS Lite is locked open, it requires some amount of force (torque) to break it loose from locked position. That force may not feel much since you are closing it from the farther end of the lid, but the amount force at the hinge is great.
Since the plastic there is too weak for that kind of force, it cracks when trying to get it out of locked position.
It shouldn't crack upon opening, because it doesn't lock in the closed position.
It also seems that it's possible this happens after amounts of time of closing.
NOTE: The hinge having the locks (clicks you hear), is ONLY on one side. The other side does not have the locking hinge, that means great amount of force is required on ONE hinge to keep it locked open.
You can see the locking mechanism only on one side of this disassembled DS Lite:
http://i35.photobucket.com/albums/d165/fatfree69/photo1.jpg
http://i35.photobucket.com/albums/d165/fatfree69/photo2.jpg
http://i35.photobucket.com/albums/d165/fatfree69/photo3.jpg
Here is a picture to illustrate what I'm trying to say (rought idea of the hinge):
http://i35.photobucket.com/albums/d165/fatfree69/hinge.gif
Also, the hinge doesn't have to be made like that for the crack to occur upon closing. The hinge could be a different type, but the resistance of the locked position is the same, so the crack will always occur on the outter side since thats the side we are putting force to close it.
If the locking hinge was on the otherside as well, then the amount of force for each hinge is divided in half since the locking force isn't relied only on one anymore, but two hinges, which will lower the chances of cracking.
BTW: I initiated this thought because "Unknownbeast" had started this theory on the other thread, and would like to expand the idea more here.
Now that we are aware that many people have had the cracked hinge on their DS Lite, I may have a really good theory about this.
The crack results from closing the DS Lite from an open, "LOCKED" position.
When the DS Lite is locked open, it requires some amount of force (torque) to break it loose from locked position. That force may not feel much since you are closing it from the farther end of the lid, but the amount force at the hinge is great.
Since the plastic there is too weak for that kind of force, it cracks when trying to get it out of locked position.
It shouldn't crack upon opening, because it doesn't lock in the closed position.
It also seems that it's possible this happens after amounts of time of closing.
NOTE: The hinge having the locks (clicks you hear), is ONLY on one side. The other side does not have the locking hinge, that means great amount of force is required on ONE hinge to keep it locked open.
You can see the locking mechanism only on one side of this disassembled DS Lite:
http://i35.photobucket.com/albums/d165/fatfree69/photo1.jpg
http://i35.photobucket.com/albums/d165/fatfree69/photo2.jpg
http://i35.photobucket.com/albums/d165/fatfree69/photo3.jpg
Here is a picture to illustrate what I'm trying to say (rought idea of the hinge):
http://i35.photobucket.com/albums/d165/fatfree69/hinge.gif
Also, the hinge doesn't have to be made like that for the crack to occur upon closing. The hinge could be a different type, but the resistance of the locked position is the same, so the crack will always occur on the outter side since thats the side we are putting force to close it.
If the locking hinge was on the otherside as well, then the amount of force for each hinge is divided in half since the locking force isn't relied only on one anymore, but two hinges, which will lower the chances of cracking.
BTW: I initiated this thought because "Unknownbeast" had started this theory on the other thread, and would like to expand the idea more here.