HP -28S Manual page 289

4. Tip the calculator to remove the old batteries.
5. Insert three new batteries. Orient the batteries as shown on the
diagram on the back of the calculator. Be certain to observe the
polarities (+ and -) as shown.
6. Press the batteries into the compartment using the portion of the
battery door that extends beyond the metal contact plate. Press
down until the contact plate is lined up with the grooves on the
calcula tor case.
7. Slide the contact plate into the grooves. If necessary, use your
finger to push the batteries into the compartment so that the
door can slide over them. Slide the door until it latches into
place.
288 A: Assistance, Batteries, and Service
I