Motorola V8088 - Manual (Page 43)

V8088
Repair Chart
Table 2. GSM V8088 Cellular Telephone: Troubleshooting and Repair Chart. (Assembly Replacement
Level).
SYMPTOM PROBABLE CAUSE VERIFICATION AND
REMEDY
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 circuit board
Failure. Replace the Keypad board. Temporarily connect a
+3.6 V dc supply to the battery connectors Depress
the PWR button; if unit turns on and stays on,
disconnect the dc power source and reassemble the
telephone with the new Keypad board. If the fault is
not cleared then proceed to e.
e) Display circuit failure Disassemble unit and insert Main RF / Logic PCB
into new front Hsng with Flip. Inset Battery and
depress PWR button. Ensure unit stays on, if OK
reassemble unit in new housing assembly
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
Display board faulty. Remove rear housing from unit, check general
condition of flex connector if OK check that the Zif
connector is fully pressed down and that the flex
collars are flush with the plastic of the connector.If
not check Zif to PCB connections, if faulty
connector, replace RF / Logic PCB. If Ok proceed to
b.
b) Display board is
Defective. Substitute the good RF / Logic PCB into a known
good front Hsng /Flip (with good Display circuit
board), if the fault is cleared rebuild with new Hsng /
Flip Assy. If the fault is not cleared, re-install into
the original front Hsng / Flip Assy and proceed to c.
SYMPTOM PROBABLE CAUSE VERIFICATION AND REMEDY
c) Logic/RF Board Assembly Replace Logic/RF Assembly (refer to symptom 1c).