Olympus PT-019 - Manual (Page 27)

E-26
6. Maintaining the Waterproof Function
Remove the O-ring.
Open the Case and remove the O-ring from the Case.
Removal of the O-ring
ᕃ Insert the O-ring removal pick between the O-ring and the wall of
the O-ring groove.
ᕄ Move the tip of the inserted pick under the O-ring. (Take care not
to damage the O-ring groove with the tip of the pick.)
ᕅ Hold the O-ring with your fingertips after it has come out of the
groove and remove it from the Case.
Remove any sand, dirt, etc.
After visually checking that dirt has been removed from the O-ring,
checking for attached sand and other foreign matter, as well as for
damage and cracks can be done by squeezing the entire circumference
of the O-ring lightly with your fingertips.
Use a clean cloth (that doesn't shed fibers), a toothbrush, tissue paper
or the like, to remove any foreign matter from the O-ring groove. Clean
the O-ring contact surface on the front lid in the same way to remove
any sand and dirt.