Tait TM8100 mobiles, Service Manual

Page: 361 / 620

TM8100/TM8200 Service Manual Transmitter Fault Finding (25W) 361
© Tait Electronics Limited November 2007
Figure 12.7 Measurement and test points for diagnosing faults in the biasing of the PAs and PA
driver
PIN
SWITCH
AND
LPF
R336
R347
DIREC- TIONAL
COUPLER
PA
s
BUFFER AMPLIFIER BUFFER AMPLIFIER
POWER CONTROL
DRIVER
EXCITER
BIAS
LIMITER
SHAPER
AND
LEVEL
SHIFTER
SHAPER
AND
LEVEL
SHIFTER
SHAPING
FIL
TER
FRE-
QUENCY
SYNTHE-
SIZER
CDC
TX
DR
V
BIAS
CDC
TX
FIN
BIAS1
CDC
TX
FIN
BIAS2
CDC
TX
PWR
CTL
TX
FWD
PWR
TX
REV
PWR
CODEC
AND
AUDIO
CIRCUITR
Y
SIGNAL
TYPES
RF ANALOG
SET
PWR
TEST
POINT
SET
PWR
TEST
POINT
DR
V
TEST
POINT
DR
V
TEST
POINT
P
IN8O
F
IC303
PIN
8
OF
IC303
P
IN9O
F
IC303
PIN
9
OF
IC303
PIN
10
OF
IC303
PIN
10
OF
IC303
P
IN5O
F
IC303
PIN
5
OF
IC303
FIN1
TEST
POINT
FIN1
TEST
POINT
FIN2
TEST
POINT
FIN2
TEST
POINT
PWR
TEST
POINT
PWR
TEST
POINT
PIN
14
OF
IC301
PIN
14
OF
IC301
P
IN8O
F
IC301
PIN
8
OF
IC301
P
IN1O
F
IC301
PIN
1
OF
IC301
GA
TES
OF
Q309,
Q310
GA
TES
OF
Q309,
Q310
GA
TE
OF
Q306
GA
TE
OF
Q306