HP HP-20S - Page 117

B If the calculator won’t turn on (nothing is visible in the display):
1 -
2.
3.
4'
Attempt to reset the calculator (page 113).
Attempt to erase Continuous Memory (page 114).
If the calculator fails to respond after step 1 or 2, replace the
batteries (page 111).
If the calculator fails to respond after step 3, remove the bat-
teries (page 111) and lightly press a coin against both
calculator battery contacts. Put the batteries back in and turn
on the calculator. It should display ALL CLr.
If steps 1 through 4 fail to restore calculator operation, it re-
quires service.
B if the calculator doesn’t respond to keystrokes (nothing hap-
pens when you press any of the keys):
1-
2.
Attempt to reset the calculator (page 113).
If the calculator fails to respond after step 1, attempt to erase
Continuous Memory (page 114). This will erase all the in-
formation you've stored.
If the calculator fails to respond after steps 1 and 2, remove
the batteries (page 111) and lightly press a coin against both
calculator battery contacts. Put the batteries back in and turn
on the calculator. It should display ALL CLer.
If steps 1 through 3 fail to restore calculator function, the cal-
culator requires service.
B If the calculator responds to keystrokes but you suspect that it
is malfunctioning:
1.
2.
3.
Do the self-test (described below). If the calculator fails the
self test, it requires service.
If the calculator passes the self-test, it is quite likely that
you've made a mistake in operating the calculator. Try reread-
ing portions of the manual, and check “Answers to Common
Questions” on page 109.
Contact the Calculator Support department. The address and
phone number are listed on the inside back cover.
Assistance, Batteries, Memory and Service 115