Panasonic KX-FT21BX Service Manual page 166

LINERX
Analog Front End
(IC5)
MOM RX ENB
TEL RX ENB
VOL
ASIC (IC1)
MODEM
Analog Unit Block Diagram
T1
LINETX
Analog Board
Digital Board
MTX ENB
H/STX
H/STX MUTE
H/SRX
H/SRX ENB
SP AMP
SPOUT
R32
BELL
C35
PC
R37
SPEAKER
CN2
SW2
R4
R2
SP-MUTE
RLY1
SA1
POS1
SA2
+24V
RLY1
LINE-RLY
CN3
R3
HOOK
SW1
R1
C2
CN4
T
R
CN5
R1
T1
HANDSET
PAPER
C1