A1018s/A1018sc Standard Electrical Repair
4/00021-2/FEA 209 544/16.B 33 (42)
• If all soldering is correct, replace the buzzer (H600). Try the buzzer again by
starting the board in the fixture, the buzzer should sound because there is no SIM
card inserted.
• If the fault remains, make sure R606 is ok by measure the voltage at both sides of
it (VBATT). VBATT should also exist at H600:3. If it doesn´t, is there a foil
damage. If the voltage is correct, replace V606 and R651.
* If that doesn´t fix it, measure the resistance from R651 (marked side) to
D600:91. It should be ~0 Ohm, otherwise is there a foil damage and the board
has to be discarded
• Replace D600.
If the fault still remains, send the board to the next repair level.
9.3 The background illumination to the display
is missing or faintly glowing.
Open the phone and check for liquid damages.
Make sure all LEDs (H651, H652, H653 and H654. All four class A, Fig. 9.2) are
mounted and correctly soldered.
Fig. 9.2
Give the board power and start the board.
• If only a couple of the LEDs are faulty, replace them.
• If none of the LEDs are lit, measure the resistance at one of them.
* If the resistance is ~0 Ohm, is there a foil damage in at least one of the
LEDs. Remove the LEDs one by one in the following order: H654; H651,
H653 and finally H652. Measure the resistance after each removal. When the
resistance increases, the fault is fixed.
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