Troubleshooting Chart - Motorola T720 Instruction Manual

Level 3 Service Manual

Troubleshooting Chart

Table 4. PF B65 Telephone: Level 1 and 2 Troubleshooting Chart
Symptom
1. Telephone will not turn on or stay on.
2. Telephone exhibits poor reception or
erratic operation such as calls frequently
dropping or weak or distorted audio.
3. Display is erratic, or provides partial or
no display.
4. Incoming call alert transducer audio
distorted or volume is too low.
6881040B60
Probable Cause
a) Battery either discharged or
defective.
b) Battery connectors open or
misaligned.
c) Transceiver board assembly
defective.
d) keyboard assembly failure.
a) Antenna assembly defective.
b) Transceiver board assembly
defective.
a) Transceiver board connections
faulty.
b) Flip assembly defective.
c) Transceiver board assembly
defective.
Faulty transceiver board assembly. Replace the transceiver board assembly (refer to
August 01, 2002
Troubleshooting
Verification and Remedy
Measure battery voltage across a 50 ohm (>1
Watt) load. If the battery voltage is <3.25 Vdc,
recharge the battery using the appropriate battery
charger. If the battery will not recharge, replace the
battery. If battery is not at fault, proceed to b.
Visually inspect the battery connectors on both the
battery and the telephone. Realign and, if
necessary, either replace the battery or refer to a
Level 3 Service Center for the battery connector
replacement. If battery connectors are not at fault,
proceed to c.
Remove the transceiver board assembly.
Substitute a known good assembly and
temporarily reassemble the unit. Depress the
PWR button; if unit turns on and stays on,
disconnect the dc power source and reassemble
the telephone with the new transceiver board
assembly. Verify that the fault has been cleared. If
the fault has not been cleared then proceed to d.
Replace the keyboard assembly. Temporarily
connect a +3.6 Vdc supply to the battery
connectors. Depress the PWR button. If unit turns
on and stays on, disconnect the dc power source
and reassemble with the new keyboard assembly.
Check to make sure that the antenna pin is
properly connected to the transceiver board
assembly. If connected properly, substitute a
known good antenna. If the fault is still present,
proceed to b.
Replace the transceiver board assembly (refer to
1c). Verify that the fault has been cleared and
reassemble the unit with the new transceiver board
assembly.
Remove rear chassis assembly from unit, check
general
condition of flexible printed cable (flex). If the flex is
good, check that the flex connector is fully pressed
down. If not, check connector to transceiver board
connections. If faulty connector, replace the
transceiver board assembly. If connector is not at
fault, proceed to b.
Temporarily replace the flip assembly with a known
good assembly. If fault has been cleared,
reassemble with the new flip assembly. If fault not
cleared, proceed to c.
Replace the transceiver board assembly (refer to
1c). Verify that the fault has been cleared and
reassemble the unit with the new transceiver board
assembly.
1c). Verify that the fault has been cleared and
reassemble the unit with the new transceiver board
assembly.
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