Sharp 902SH Service Manual page 35

4. Battery does not charge/Charging does not complete.
4.1. Battery does not charge.
When the AC charger is connected, is the volt-
age of TP1301 higher than that of the battery?
YES
Is 7.0 V or lower on TP1301?
YES
Is the voltage of TP1204 is higher than that of
the battery?
YES
Does the handset (phone) turn on?
YES
Is the voltage of TP1211 is higher than that of
the battery?
YES
Is the resistance between TP1207 and GND
(TP1209) 82 k ohms?
YES
LED1200 and R1248 are defective.
4.2. Charging does not complete.
Is 4.2 V or more on TP1211?
YES
Is 4.2 V or more on TP1211 for over 30 min-
utes?
YES
Is the temperature of the front cabinet (key
side) below 35°C?
YES
Charge parameter data is corrupted.
CONFIDENTIAL
The AC charger is defective. CN1300 is
NO
mounted improperly or in poor contact.
The AC charger is defective.
NO
Q1212, IC1201, R1200, R1201, R1261, C1241
NO
and C1200 are defective.
Go to the section "3. Power dose not turn on."
NO
(see page 2-26)
Is the red LED (LED1200) flashing?
NO
Is the ambient temperature between 5 and
35°C?
IC501 and IC1200 are defective or mounted
improperly.
S terminal of the Li-Ion battery is defective.
NO
CN1200 is in poor contact.
Is the temperature of the front cabinet (key
NO
side) below 35°C?
Is 5.0 V or lower on TP1301?
The Li-Ion battery is defective, charge parame-
ter data is corrupted, or IC1200 is defective.
Charging time depends on handset (phone)
NO
use, or the degree of the battery deterioration.
(Wait for more than 30 seconds.)
Depending on the temperature, charging may
NO
take longer.
2 – 27
NO
YES
NO
YES
NO
YES
NO
YES
902SH
IC1200 is defective,
and charge parame-
ter data is corrupted
Temperature abnor-
mality.
Depending on the
temperature, charg-
ing may take longer.
Go to the section
"4.1. Battery does not
charge."