Check whether the zipper is stuck on fabric, thread, or debris
Gently pull the fabric away from the zipper teeth
Remove dirt or lint with tweezers or a small brush
Rub a graphite pencil, soap, or zipper lubricant along the teeth
Slide the zipper slowly back and forth
If the zipper pull is loose, squeeze it gently with pliers
If the slider is misaligned, realign it carefully on the teeth
If the zipper teeth are separated, use pliers to close the slider slightly
If a tooth is bent, straighten it with pliers
If the zipper pull is broken, replace the pull tab or use a paperclip as a temporary fix
If the slider is damaged, replace the slider
If the zipper stops at one spot, inspect for damaged teeth or fabric caught in the track
If the zipper is beyond repair, take the backpack to a repair shop or replace the zipper