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lunedµ 20 dicembre 1999
note: all the signal & voltage present
in this procedure has to be clear and
at correct level ; compare them with a
good pcb
Whenever you have a signal with a simbol star ( * ) means that it is active low if you select this kind of way , while
RF IS PRESENT ,
NEVER MIND
LEVEL BUT IS
Check on U301:
pin 3 DCS_TX_VCO see on Q130 , Q140.
pin 8 GSM_TX_VCO see on Q130 ,
Q140.
pin 10 SF_OUT see on C246 ( comes from
U200 9.
pin6 CP TX check for this Q310 , Q311 ,
U310 , U200 , R305 , R306 , R307.
DM_CS , TX_EN , they comes from U800
V1_SW comes from Q913
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 1 : You can use this procedure for GSM way & DCS way.
the same point of measure will be high for other way.
Differences betwen GSM & DCS way are:
TX_GSM*DCS
used for adjust all RF TX way for GSM/DCS choise
for any problem check on Q160
DCS_SEL comes out from U200 (or pin 2 U110)
GSM_SEL comes out from U110 pin 4
-10 V comes out from U904.
DCS_TX_VCO , GSM_TX_VCO
for any problem check Q130
Connect on J300 connector an RF spectrum
analyzer , set pcb in test mode and digit
following test command:
110062# 1215# 40# for a test in GSM way.
110700# 1215# 40# for a test in DCS way.
Check for RF signal presence at frequency =
902.4 MHz for GSM or 1747.8 MHz for DCS .
DIRTY
Is RF TX signal
at GSM/DCS
frequency present
on U301 pin 4 ?
NO
- MOTOROLA CONFIDENTIAL PROPRIETARY -
Dual band Taishan level 3 debug rev 1.0
RF IS NOT
PRESENT
YES
L365 , L325 , L326 ,
C397for missing or dry joint
, else check for faulty Q110 ,
-5V cc see U903
TX_EN , RX_EN comes
NO TX
GSM/DCS
RF IS
PRESENT
BUT IS LOW
Is RF TX
GSM/DCS
NO
present on
Q370 DRAIN?
YES
Check:
U100.
from U800
Go to "
B " on
pag.08
Page 7
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