Motorola T189, Service Manual

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Page 14
lunedµ 20 dicembre 1999
- MOTOROLA CONFIDENTIAL PROPRIETARY -
Dual band Taishan level 3 debug rev 1.0
Supply pcb using "pcb test cable " code AE20101903 ,set pcb in test mode, digit test
command:
434# audio on speaker
36# loop back on
4707# max volume
Check which way doesn' t works correctly.
Note: if each way doesn't works check on U900 for PRESENCE OF " SPI AUDIO BUS " :
Tp 828 CK 512 KHz , Tp 831 data
Tp 830 data , Tp 829 8 KHz ck.
If they are not presents check on Tp 823 or C825 for 13 MHz ck , if not ok problem could
be U800 , else U900.
INTERNAL
MIKE DOESN'T
WORK.
HEADSET
MIKE DOESN'T
WORK.
NO AUDIO TX on
microphone/headset
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
Check for "Mic bias" = 1,4 Vcc
presence on C923 , if not ok
check for dry joint , misssing or
unsoldered issues on R927 , R926
, C934 , C927 ;if ok check for
same issues on C923 , R925 ,
L927.
Finally problem could be U900.
Check in order:
_J504 "headset jack" for faulty or unsoldered
pins.
_0,6 V presence on R977with jack on and 2,7
Vcc with itself off , if not correct check for V2
=2,7 Vcc presence on R976 , else check R976 ,
R977 , L1004 , VR 977 for missing , dry joint or
unsoldered issues.
_L500 , C1520 , C510 , C931 , R930 , C927 ,
R928 , L928 for same issues.
_Mic_bias = 1 Vcc presence on C931, if not
correct ,check R957 for missing ,dry joint or
unsoldered issues.