TROUBLESHOOTING
ETrbl5 68P09304A85
19/07/97 19
Table 1. DCS 1800 StarTAC Cellular Telephone Troubleshooting and Repair Chart (Assembly Replacement Level).
SYMPTOM PROBABLE CAUSE VERIFICATION AND REMEDY
1. Personal telephone will not turn on
or stay on.
a) Battery pack either discharged
or defective.
Measure battery voltage across a 50 ohm (>1 Watt) load. If the battery
voltage is <3.25 V dc, 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 connectors open or
misaligned.
Visually inspect the battery connectors on both the battery assembly and
the portable telephone. Re-align and, if necessary, replace either the
battery or the battery connector assembly. Removing the battery connector
assembly has to be done with extreme care to avoid damaging the PCB.
If battery connectors are not at fault, proceed to c
c) Logic/RF Board Assembly
defective.
Remove the Logic/RF 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 Logic/RF Board assembly. Verify that the fault
has been cleared. If the fault has not been cleared then proceed to d.
d) Keypad/Display circuit board
failure.
Replace the Keypad/Display board. Temporarily connect a +3.6 V dc
supply to the battery connectors;(refer to pinouts in the diagram on
previous page). Depress the PWR button; if unit turns on and stays on,
disconnect the dc power source and reassemble the telephone with the
new Keypad/Display board.
2. Personal telephone exhibits poor
reception and/or erratic operation
(such as calls frequently dropping,
weak and/or distorted audio, etc.).
a) Antenna is defective. Check to make sure that the antenna pin is properly connected to the Logic/
RF assembly. If OK, substitute a known good antenna . If the fault is still
present, proceed to b.
b) Logic/RF Board Assembly
defective.
Replace Logic/RF Assembly (refer to symptom 1c). Verify that the fault
has been cleared and re-assemble the unit with the new PCB.
3. Display is erratic, or provides
partial or no display.
a) Mating connections to/from
Keypad/Display board faulty.
Gain access to Keypad/Display / main board as described in the
DISASSEMBLY instructions in this manual. If connections are faulty
then replace the RF/Logic assembly and/or the Keypad/Display board as
necessary. If connections are not at fault, replace the original boards and
proceed to b.
b) Keypad/Display board is
defective.
Substitute a known good Keypad/Display circuit board, if the fault is not
cleared, re-install the original Keypad/Display PCB and proceed to c.
c) Logic/RF Board Assembly
defective.
Replace Logic/RF Assembly (refer to symptom 1c). Verify that the fault
has been cleared and re-assemble the unit with the new PCB.
Repair Chart
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