Level 1-2 Service Manual
Troubleshooting
Aug.15, 2006
39
Troubleshooting
W370/W375 Troubleshooting Chart
Level 1 and 2 Troubleshooting Chart
Symptom
Probable Cause
Verification and Remedy
1. Phone will not turn on or stay on.
a) Battery either discharged or
defective.
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.
b) Battery terminals open or
misaligned.
Visually inspect the battery terminals on both the
battery and the phone. Realign and, if necessary,
either replace battery or refer to a Level 3 Service
Center for the battery connector replacement. If
battery terminals are not at fault, proceed to c.
c) Keypad defective.
Replace the keypad. Temporarily connect a +3.6
Vdc supply to the battery terminals. Press and hold
the PWR button. If phone turns on and stays on,
disconnect the dc power source and reassemble
with the new keypad.
2. Phone exhibits poor reception or
erratic operation such as calls
frequently dropping or weak or
distorted audio.
Connections to or from lower
PCB defective.
Check connection between the antenna and the
lower PCB.
3. Display is erratic, or provides
partial or no display.
LCM defective.
Replace the LCM. Verify that the fault has been
cleared and reassemble the phone with the new
LCM.
4. Incoming call alert transducer
audio distorted or volume is too low.
Speaker defective.
Replace the speaker as described in the
procedures. Verify that the fault has been cleared
and reassemble the phone with the new speaker.
5. Phone transmit audio is weak.
(usually indicated by called parties
complaining of difficulty in hearing
voice).
Microphone defective.
Replace the microphone as described in the
procedures. Verify that the fault has been cleared
and reassemble the phone with the new
microphone.
6. Receive audio from earpiece
speaker is weak or distorted.
a) Connections to or from lower
PCB defective.
Check connection between the antenna and the
lower PCB. If the connection is OK, proceed to b.
b) Earpiece Speaker defective.
Temporarily replace the earpiece speaker with a
known good earpiece speaker. Ensure good
connection. Place a call and verify improvement in
earpiece audio. If fault is cleared, reassemble the
phone with the good earpiece speaker.