Philips MC-M250 Service Manual page 27

CIRCUIT DIAGRAM - COMBI BOARD (Part 2)
1330 B18 2331 G6 2334 E7 2337 G13 2340 E13 2343 B16 2346 F17
1331 F18 2332 E6 2335 G7 2338 F13 2341 A15 2344 B16 2347 H15
2330 C10 2333 F7 2336 F7 2339 H13 2342 B15 2345 F17 2348 H14
1 2 3 4
COMBI BOARD - POWER AMPLIFIER PART
A
B
C
D
E
F
from
Source Selection and Sound Control Part
G
H
I
J
K
L
1 2 3 4
11 - 2
2349 J14 2352 K7 3330 H7 3333 G7 3336 F12 3339 A14 3342 B15
2350 I8 2353 J9 3331 G6 3334 F7 3337 H12 3340 C14 3343 G12
2351 C8 2354 J11 3332 E6 3335 G12 3338 E12 3341 B15 3344 E12
5 6 7 8
4335
MUTE
+5V6
(forseen only) 3356
22K
3358 T330
3354 4K7
2351
10K
4u7
7334
BC847B
7330
(forseen only)
2334 AN7125
150n
T344 2332 3332
R
10K 4334
150n 6
0V
3334 2336
3.1V
220p
6K8
3.25V
(forseen only)
0V
5
0/2.2V
9
(forseen only)
2333
0V 8
150n
T343 2331
3331
L
4333
150n 10K
3333 2335
6K8 220p
(forseen
only)
+12V
3330
3K3
2350
100u
T336
T331
6333
3359 3361
STANDBY
1N4148 6K8 100R
2352 3360
47u 100K
5 6 7 8
3345 G12 3348 I9 3351 J16 3354 C6 3359 K7 4333 G7 5331 F12
3346 E12 3349 I10 3352 J15 3356 B7 3360 K8 4334 E7 5332 E12
3347 I11 3350 L10 3353 J14 3358 B7 3361 K8 4335 A6 5333 G12
9 10 11 12 13
9330
+AMP
T333
2330
4u7
T332
5334
360n
3346
3338
10K
1
2R2
VCC
5.8V 5332
OUT1+ 2 4.7V
3344
360n
IN1 GND1 3
10K
3336
4.7V 5.8V
OUT1- 4
2R2
STB
STB
VREF
MUTE
MUTE
5.8V 5331
10 4.7V
OUT2-
360n
IN2 GND2 11
3343
4.7V 5.8V 3335
OUT2+ 12
10K
2R2
GND
5333
7
3345
360n
10K
3337
2R2
POWERSTAGE
3348
3347
PROTECTION
22K 22K
3349
22K
BC857B BC857B
BASS_ALC
7332 7331
7.2V
to 3547/3548
7.2V 6.2V 6.2V
T335
DIGITAL SOUND
CONTROL (DSC)
2353 2354
0V
10n 10n
7333
BC847B
3350 (230V MAINS SUPPLY ) DC VOLTAGES MEASURED IN :
47K
V CD Mode 1KHz , 0dB track, DSC "OPTIMAL", DBB "OFF", INCR "OFF", VOLUME "20"
V
Tuner Mode 1KHz , df "22.5kHz", DSC "OPTIMAL", DBB "OFF", INCR "OFF", VOLUME "20"
V Standby Mode
V
MUTE OFF/ON
9 10 11 12 13
11 - 2
5334 D12 6333 K6 7332 J9 9330 B11 T332 D9 T335 J12 T338 B16
6331 I15 7330 E8 7333 K9 T330 B8 T333 C10 T336 J8 T339 F17
6332 I14 7331 J11 7334 C6 T331 K8 T334 J13 T337 B16 T340 F17
14 15 16 17
HEADPHONE SOCKET
2341
3339
7
120R
47u
L 4
3341
2343
560R 1n
T337
3
L
2
R
T338
5
3342
2344
560R
1n
R
6
2342
3340
1
120R 47u
2340
220n
T339
2345
2338
22n
220n
T341
T342
T340
2346
22n
2337
220n
2339
220n
2348 2347
47u 47u
6332 6331
1N4148
1N4148
3352 3351
T334
3353
1K 1K
47R
2349
100u
14 15 16 17
T341 F17 T344 E5
T342 F17
T343 G5
18 19
A
1330
B
16 - 150 ohm
C
D
E
1331
L 1
LS BOX
8R
L 2
left
F
3
R
LS BOX
4 8R
R
right
Clickfit
socket
G
H
I
J
K
L
18 19