TM-271A/271E
9
Display Unit (X54-3450-10)
Ref. No.
Parts name
Description
IC3
IC
LCD controller
Q6
Transistor
DC switch
Q9
Transistor
LCD backlit switch
Q10
Transistor
Key backlit switch
Q12
Transistor
Brightness function switch
D2~4
LED
Key backlit
D19~30
LED
LCD backlit
D31
Diode
Reverse connection protection
TX-RX Unit (X57-685X-XX)
Ref. No.
Parts name
Description
IC31
IC
Voltage regulator (8C)
IC32
IC
Voltage regulator (5C)
IC33
IC
Voltage regulator (5M)
IC34
IC
Voltage detector (reset)
IC35
IC
Voltage detector (int)
IC66
IC
EEPROM
IC101
IC
CPU
IC161
IC
Digital potentiometer
IC201
IC
MIC amplifier / IDC
IC202
IC
MIC amplifier / Splatter filter
IC203
IC
Buffer amplifier / SUM amplifier
/ DC amplifier / 1/2 Vcc
IC204,205
IC
Single analog switch
IC251
IC
Audio filter
IC252
IC
Audio amplifier
IC301
IC
FM demodulation
IC401
IC
PLL synthesizer
IC402
IC
Divider (Hetero)
IC501
IC
APC controller
Q31,32
Transistor
DC switch (SB) / Active when power is on
Q33,34
Transistor
DC switch (8R) / Active while RX
Q35,36
Transistor
DC switch (8T) / Active while TX
Q61
Transistor
Over voltage detection / Active when
PS voltage is more than 18V
Q86,87
Transistor
Beat shift / Active while beat shift is on
Q201
Transistor
AGC / MIC mute
Q251
Transistor
Buffer amplifier / RX audio
Q252,253
FET
AF mute / Active while AFM is H
Q254
Digital transistor
AF mute / Active while SPM is H
Q255
Transistor
AF mute / Active while AMPSW is H
Q301
Transistor
Noise amplifier / SQL amplifier
Ref. No.
Parts name
Description
Q302
Transistor
Buffer amplifier / 16.8MHz 3rd over tone
Q351
Transistor
IF amplifier
Q352
FET
Mixer
Q353
FET
RF amplifier / LNA
Q354
Transistor
PC/TV switch
Q402,403
Transistor
Charge pump
Q404
Transistor
RF amplifier / PLL F in
Q405
FET
RX VCO
Q406
FET
TX VCO
Q407
FET
T/R switch
Q408
Transistor
T/R switch
Q410
Transistor
Buffer amplifier / Output of VCO
Q411
Transistor
RF amplifier / Output of VCO
Q440
Transistor
Lipple filter
Q501,502
Transistor
RF amplifier / Drive stage
Q503
FET
RF amplifier / Drive amplifier
Q504
FET
RF amplifier / Final amplifier
D1
Diode
Surge absorption / CM
D2
Diode
Surge absorption / MIC key
D3
Diode
Surge absorption / RXD
D4
Diode
Surge absorption / PTT
D5
Diode
Surge absorption / SQC
D6
Diode
Surge absorption / PKS
D31
Diode
Reverse connection protection
D32
Poly switch
Current protection
D61,62
Diode
Over voltage detection
D201
Diode
OR gate / MIC mute, AGC
D202
Diode
AGC
D251
Diode
Limiter
D301
Diode
Detection
D302,303
Diode
IF switch (Wide/Narrow)
D351~354
Varicap
RF BPF tuning
D401
Diode
Ripple filter
D402
Diode
Voltage dropped
D403,404
Varicap
RX VCO
D405,406
Varicap
TX VCO
D407
Varicap
Modulation
D408
Diode
Lipple filter
D409
Diode
RF switch (TX/RX)
D501,502
Diode
Temperature compensation
D503
Diode
Voltage protection
D602,603
Diode
ANT switch
D605
Diode
ANT switch
D606,607
Diode
APC voltage detect
D608
Diode
Temperature compensation
COMPONENTS DESCRIPTION