L7089 / L7189 Repair Chart Table 2. GSM L7189 Cellular Telephone: Troubleshooting and Repair Chart. (Assembly Replacement Level). SYMPTOM PROBABLE CAUSE VERIFICATION AND REMEDY of 48 European Customer Services 28 Personal telephone will not turn on or stay on a) Battery pack either discharged or defective Measure battery. If the battery voltage is 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 housings.
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 (see personality transfer). Verify that the fault has been cleared. If the fault has not been cleared then proceed to d. d) Display circuit failure Disassemble unit and remove LCD module and insert known good module. Insert 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 into the Logic/ RF assembly. If OK, substitute a known good antenna and test in a call. 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 LCD Module faulty. Dissasemble unit, check general condition of pads to display.
If OK proceed to b. b) LCD module is Defective. Substitute a known good LCD module onto the suspect board and connect to DC Pwr supply. Depress PWR and ensure display is now correct, if Ok rebuild unit with new LCD module if LCD module is not at fault 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.