Motorola T189, Service Manual

Page: 71 / 88

Page 8
lunedµ 20 dicembre 1999
- MOTOROLA CONFIDENTIAL PROPRIETARY -
Dual band Taishan level 3 debug rev 1.0
NO TX
GSM/DCS
" B "
Is RF signal at 902,4
MHz ( GSM ) or at
1747,8 MHz ( DCS )
on Q331 collector
Is RF GSM/DCS
signal present on
Q330 collector
Is RF GSM/DCS
signal present on
Q320 collector
Check Q320 for correct bias :
collector = 2 V RF_V2 see on
L322
, R300 base = DM_CS se on
R326 , it comes from U 800
else be sure to have correct RF
signal on U301 pin 1 ,if not ok
go to " C " on page 07.
Check C1619 , R301 ,
CR320 , L320 , C326 ,
Q330 for correct bias:
collector = 3,3 V REG B+
,see for this Q332 , Q333;
base = 1 V see R330 , PAC
IC bias on pag. 09.
Check R304 , L331 , C315
, and Q331 for correct bias:
REG B+ = 3,3 V voltage on
collector ,see for this Q332 ,
Q333.
0,4 V on base see for this L333 ,
R302 , CR330 , R387,else PAC
IC bias on page 09
Check Q370 for correct bias:
drain = B+ voltages
gate = 1,3 V see for this
L370 , L336 , R370 presence
,else PAC IC bias on pag.09
YES
NO
NO
YES
NO
YES