Apple Macintosh PowerBook 1400 - Manual (Page 180)

14 Replace the speaker grill by lowering it into the opening above the top row of keys. Slide
the grill to the right to secure it.
Position it so that the three downward-pointing tabs are at the right front of
the grill. The tabs click into place when you slide the grill to the right.
Lower the speaker grill,
then slide it to the right.
180 Appendix C