64 © 2002 Motorola, Inc.
Product Support Tools T720
Symptom
Probable Cause
Verification and Remedy
1. Phone will not turn
on or stay on.
a) Battery either
discharged or defective.
1. Measure battery voltage across a 50 ohm (>1
Watt) load.
2. If the battery voltage is <3.4 V DC, recharge the
battery using the appropriate battery charger.
3. If the battery will not recharge, replace the
battery.
b) Battery connector
open
or misaligned.
1. Visually inspect the battery connectors on both
the battery pack and the transceiver, including the
solder connections from the battery connector to
the main PC board.
2. Realign the contacts or, if necessary, replace
either the battery or battery connector.
c) Transceiver Board
defective.
1. Replace the keypad membrane with a known
good part.
2. Temporarily connect 4.5 V DC to the battery
contacts.
3. Depress the PWR button; if unit turns on and
stays on, disconnect the power source and reas-
semble the phone with the new keypad membrane.
d)Transceiver Board
Debugging Follow the
no turn on Debug proce-
dure.
1. Remove the Transceiver Board. Substitute a
known good board.
2. Temporarily connect 4.5 V DC to the battery
contacts.
3. Depress the PWR button; if unit turns on and
stays on, disconnect the power source and reas-
semble the phone with the new RF/Audio-Logic
board and re-test phone.
2. Phone exhibits
poor reception and/or
erratic operation
(such as calls
frequently dropping,
weak and/or distorted
audio, etc.)
a) Defective antenna or
damaged antenna
connector.
b) Defective RF/ Audio-
Logic Board.
1. Replace the antenna with a known good antenna.
2. Check for loose or damaged cans.
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