2.
The flashing CHARGE (Red) indicator is also used to
indicate battery temperature outside the acceptable range
for rapid charging. This indication results from the fol-
lowing sequence: After the excessively hot or cold bat-
tery is inserted into the sleeve, the CHARGE (Red)
indicator remains ON for an approximate 10 seconds,
(which indicates normal battery voltage), and then goes
into the flashing mode.
Upon insertion of the battery into the charger, the charge
control circuitry measures the resistance of the internal
battery thermistor, via the connection from CN102 pin 3
through inter-connecting cables/PCB to the thermistor
contact on the sleeve. With a known good battery at room
temperature (25 2C), the thermistor resistance is approxi-
mately 50 K Ohms. If the CHARGE (Red) indicator is
flashing with a room temperature battery in the sleeve,
check for continuity or shorts from the battery contact to
CN102 pin 3. If there is continuity, then either IC104 or
IC103 is defective or there is a PCB pattern problem,
which necessitates replacement of the Charge Control
PCB.
FAULT CONDITION 3: Charger’s CHARGE (Red) Indica-
tor flashes with no battery in the sleeve (Stand-by condition).
This fault condition can be verified by checking voltage
between CN102 pin 4 and pin 5, with no battery in the
sleeve. If this voltage is 0 volts, there is probably a PCB
run problem between R122 and D102. If the voltage is
approximately 12.6 Vdc, check IC103 pin 9. This voltage
is generated by a regulator IC101 located on the PCB and
should be approximately 5 Vdc. If this voltage is not
present the Charge Control PCB must be replaced. If the
regulated voltage is correct, then the re-set circuitry IC
102 has failed which requires replacement of the Charge
Control PCB.
FAULT CONDITION 4: Both CHARGE (Red) and READY
(Green) indicators flash simultaneously.
The probable cause of this fault condition is shorted
components QIOI and DIOI, or defects in Q103 and
Q102. This failure requires replacement of the Charge
Control PCB.
FAULT CONDITION 5: Irregular flashing of CHARGE
(Red) indicator after the charge sequence has started.
This condition results when the voltage sense circuit
detects an excessively high voltage across the battery
which is the result of charging. Normal batteries do not
exceed the 10.5 V limit. The battery should be replaced
with a known good battery. If normal operation results,
the battery is defective. If the problem persists, the voltage
detection of the PCB has failed, which requires replace-
ment of the Charge Control PCB.
FAULT CONDITION 6: Excessive battery temperature re-
sulting from overcharge due to failure to detect minus delta
V.
If the charge control circuit fails to detect minus delta V,
the battery can be excessively overcharged which results
in high battery pack temperature. Under normal opera-
tion, the battery over temperature detect circuit would
prevent excessive over charge. Additionally, the watch
dog timer would terminate over charge based on time. The
failure to correctly terminate rapid charge by any of the
above three methods indicates failures of either the charge
control microprocessor IC 103, analog switch IC104, or
the watch dog timer IC102. Any of these failures require
replacement of the Charge Control PCB.
FAULT CONDITION 7: Premature termination of rapid
charge prior to full charge. Indication is flashing READY
(Green) indicator.
This failure mode is the result of the charge control circuit
detecting a minus delta V condition early in the charging
cycle. This condition is the result of a marginal battery or
a battery which has limited capacity and is close to the end
of its life. The battery should be discarded and replaced
with a known good battery.
FAULT CONDITION 8: Extended charge time when charg-
ing a "long battery, without overheating.
When charging a long battery, the battery length mi-
croswitch, located at the bottom of the charging sleeve,
detects the battery length which provides the correct rate
of rapid charge. If the microswitch is defective or there is
an open between the switch and the Charge Control As-
sembly, the charge control circuit may be charging at the
low level rapid charge (1.3 A 10 %) instead of the correct
level of (1.9 A 10%). Total charging current should be
checked by measuring current in the negative (-) path.
Standard Charger
The first step in trouble shooting the Universal Standard
Charger is to make a careful visual inspection of the unit for
signs of burning or overheating of components. Also check
for loose connections and cracked components. If there is no
evidence to indicate the location of the failure, the next step
is to troubleshoot by voltage measurements and/or signal
tracing. For this purpose, functional diagrams are provided.
QUICK CHECKS:
•
Check AC power cord
•
Check commercial power line voltage
•
Check using a known good battery pack
AE/LZB 119 1643
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