Motorola T189, Service Manual

Page: 75 / 88

Page 12
lunedµ 20 dicembre 1999
- MOTOROLA CONFIDENTIAL PROPRIETARY -
Dual band Taishan level 3 debug rev 1.0
NO
KEYPAD
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
Remove keypad membrane and check if
here is any issues ( dirty , track , solder )
on key contacts from S501 to S522.
Check also R500 , R501 , R502 for V2 =
2,8 Vcc presence, if all is ok probably
U800 faulty.
Note : for "VOL_UP " , "VOL_DOWN"
keys check also CR502 , while for
"PWR_ON " key check R508 for missing
or unsoldered issue ,else problem could
be U900.
NO
ALERT
Supply pcb using "pcb test cable" cod
AE20101903 , set pcb in test mode and digit test
commands 432# = tone enabled on alert way )
1513# (continuos tone ),4707# max volume .
Check for "ALRT_VCC" = 3 Vcc presence on
J510 alert pad and check for signal = 1,6 Vpp
offset = 1,4 Vcc on J511 alert pad
Check in order:
ALRT_VCC presence = 3V on Q903 pin 1 , 2 ,
5 , 6 , if not ok check on pin 4 for B+ presence
.Note: because Q903 is positioned under test
cable you are not able to check for ALRT_VCC
presence on it,so you can check this on
backlight leds anode.
Check CR510 , C1723 , C1722 , C933 for
missing , dry joint or faulty.
Finally, only if you have not any issue on audio
speaker, problem could be U900.
Check alert for faulty ,
else be sure you have not
any intermittent problem
( check U900 for this ),or
check for dirty on J510 ,
J511 alert pads.
YES
NO