If the leak was repaired, remove the loose seam tape. Use fiberglass mesh tape over the seam (its sticky on one side), then use drywall patching compound with a six inch putty knife over the seam. Cover the mesh tape but don't use too much compound so not to sand to much. Smooth out the patch as much as you can. Let dry overnight. Next day use a clean putty knife and scrape off any high spots. Use a damp sponge to smooth out the seam with the rest of the ceiling. Let dry, prime and touch up with paint.
If the leak was repaired, remove the loose seam tape. Use fiberglass mesh tape over the seam (its sticky on one side), then use drywall patching compound with a six inch putty knife over the seam. Cover the mesh tape but don't use too much compound so not to sand to much. Smooth out the patch as much as you can. Let dry overnight. Next day use a clean putty knife and scrape off any high spots. Use a damp sponge to smooth out the seam with the rest of the ceiling. Let dry, prime and touch up with paint.