Motorola D10 Service Manual page 135

BenQ
9.Handfree
a) Components shift 1. Disassembly to visually inspect the J3.
no function
b) U3 is at fault
c) Other
components are at
fault.
If audio jack (J3) pins don't contact
well with PCB pads, solder the pins
and pads together.
2. Visually inspect the R72, R32, U9, U8,
U10, R95, R33, R36, R37, R38, C60,
C63, R81, C37, C38 and D21. If any
component isn't contacted well, shift it
back to the right position.
3. If they are not shifted, proceed to b
1. Measure voltage level if VR3 and
VR2B_SW voltage level are equal
2.9V.
2. Measure the waveforms of the C60,
R41, and D21. If the C60 or R41 pins
don't output any signal when handfree
function is executed, U3 is at fault.
3. If it is not at fault, proceed to c.
1. When handfree is plugged in,
IO13ACCIN detect 0V. Then,
IO3DATA_HP_SEL outputs high level,
U8.1 pin connects to U8.4 pin and
U10.1 pin connects to U10.4 pin. If
not, maybe the U8 and U10 are at
fault. Replace the U8 or U10.
2. After IO3DATA_HP_SEL outputs high
level, measure the waveform of the
U10.4 pin. If its voltage level doesn't
drop to 1 ~ 2.6V and the voltage of the
U3.C6 pin isn't equal to 0.5 ~ 1.3V,
test it again by another handfree. If
handfree is still no function, U9, R37,
R38, D21, R6 or R9 is at fault. Visually
inspect the components. If any
component isn't contacted well or
wrong, replace the components.
3. Measure the waveforms of U9.5, U9.1,
U9.4 and U9.3 when handfree function
is executed.
4. If any pin is no signal, replace the U9.
94
Rev 1.0