Motorola T189, Руководство по обслуживанию

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Page 13
lunedµ 20 dicembre 1999
- MOTOROLA CONFIDENTIAL PROPRIETARY -
Dual band Taishan level 3 debug rev 1.0
NO AUDIO
on
SPEAKER
NOTE: check if any components mentioned is correctly
positioned , has not dry joint and is not damaged . If all is ok
replace it . If problem is still the same send BOARD IN htc.
note: all the signal & voltage present
in this procedure has to be clear and
at correct level ; compare them with a
good pcb
Power on pcb using "pcb test cable " code AE20101903 reset pcb and check on J502 & J503
speaker contacts for presence , during power up sequence , of a signal 1 Vpp offset 1,5 Vcc
Replace
speaker on
front housing
Check for VAG = 1,5 Vcc
presence on C940 , if not ok
check in order:
C940 , C938 , C926 , C925
for any faluty
If they are ok problem could
be U900
Insert on J504
connector an
headset jack ,is
power on tone
udible on speaker?
You could have an
intermittent problem ,
so check any
components of
speaker way for this
(U800 , U900).
Set pcb in test mode and
digit following test
command:
481000# , 434# , 4707# ;
is 1 KHz tone present on
speaker ?
important: remove jack
on J504 connector
Digit 432# test command (
enabled alert way for audio
use ); is 1 KHz tone present
on alert pads J510 = B+ ,
J511=tone ?
Check for faulty ,
missing or dry
joint on:
R517 ,R518 ,
R519 ,CR500.
Digit 434# test command , check
on SPI AUDIO DIGITAL:
TP 828 VCLK at 512 KHz
TP831 RX DATA
TP830 TX DATA
TP829 VFSRX at 8KHz.
If all is ok replace U900 ,else
problem could be U800.
Check for 2,7 Vcc presence on
VR977 without jack inserted
and 0,6 Vcc with jack on; if
not ok check for missing , dry
joint or unsoldered issues on
R976 , R977 , L1004 , VR 977
, J504 .
Else problem could be U800.
NO
Offset and audio
are presents but
low compared with
a good one
YES
NO
NO
YES
NO
NO
YES
NO
END
YES