Motorola D10 Service Manual page 132

BenQ
2.LCD no
a) LCD module is at
display.
fault
b) LCD module has
no power.
c) U1 is at fault
3.Keypad no Keypad bottom
function. short
4.LED no a) Components shift 1. Disassembly to visually inspect the
display
b) U1 is at fault
c) Other
components are at
fault.
1. Disassembly to visually inspect the
LCD module. If the glass is break on
the LCD, replace the LCD module.
2. If the LCD module is not break,
proceed to b
1. Visually inspect the C34 or R27 is still
on the board. If no, replace the C34 or
R27.
2. Measure the voltage of C34. If it is not
about 7.6V, the LCD driver IC is failed
on the LCD module. Replace the LCD
module.
3. If the LCD module is not break,
proceed to c
1. Power on the handset. Then measure
the waveforms of the J2.4, J2.5 and
J2.6 pins.
2. If the J2.4 pin is always low or the
other two pins (J2.5 and J2.6) are no
data, the U1 is at fault. Replace the
U1.
Disassembly to replace the keypad metal
dome.
U7, R34, BQ2, D18, D19, R39, R40,
R35, R89, R90, R91, U18, D20, U19.
If any component is shifted, shift it
back to the right position.
2. If they are not shifted, proceed to b
1. Measure the waveform of the U7.2. If
the U7.2 doesn't output any signal
when LED function is executed, U1 is
at fault.
2. If it is not at fault, proceed to c.
1. Measure the waveform of the U7.6,
BQ6.1, and BQ6.3 when LED function
is executed.
2. If any pin is no signal, replace the
component relative to that pin.
91
Rev 1.0