Onkyo HTR-548 SERIES Service Manual page 29

A
SCHEMATIC DIAGRAM/ BLOCK DIAGRAM-12
RS-232/ 12V TRIG./ IR SECTION
PART-12
1
2
3
4
B
DTR-20.3/30.3 Schematic Diagram RS-232/12VTrig/IR Section (PART-12)
U0043
BAETC-0645
L4801
BLM21PG221SN1
R4806
330
R4807
330
47
R4820
47
R4853
3 GND_VD
D4824 D4825
2 +12VTRG
2 1 2 1
1
KDS4148U
KDS4148U
Q4814
KRC102S
1
JL601B
FROM BADG-0643(PART-06)
FROM DIGITAL IN/DAC/MPU PWB
C
RS-232C
R4860
R4808
16 1
FORCEOFF EN
C4802
15 2
10K 10K
VCC C1+
C4803
14 3 1/50
GND V+
13 4 1/50
T1OUT C1-
C4806
R4809
12 5
FORCEON C2+
10K 11 6 1/50
T1IN C2-
C4807
10 7
INVALID V-
9 8 1/50
R1OUT R1IN
R4865 100
3
R4858
2
0
1
+3.3VMPU
D4819
R4866
1 2
1K
N.M
1
D4830
SIR-34ST3F
1
SIR-34ST3F
Q4812
KTA1266
8.2
R4822
8.2
R4854 Q4813
2SB1240
D4826 D4827
2 1 2 1
47
R4824
KDS4148U KDS4148U
47
R4855
D4828 D4829
2 1 2 1
KDS4148U
KDS4148U
Q4815 Q4817
KRC102S KRC102S
1 1
R4848
100(1W)
1
D E
C4801 10
223K
1
6
2
7
R4861 RS-232
3
330 8
R4862 4
330
9
5
P4801 11
U4801
KSM-603TE5B
CHGND
2
P4812
R4847
2 5 UPPER
100 6
IR IN A
D4831
4
2
12V TRG C
3
1
LOWER
P4813
5 UPPER
6
12V TRG A
4
2
3
12V TRG B
1
LOWER
P4814
R4838
5 UPPER
100
6
IR IN B
4
2
3
IR OUT
1
LOWER
DTR-20.3/DTR/30.3