Philips MC-M250 Service Manual page 28

CIRCUIT DIAGRAM - COMBI BOARD (Part 3)
0250 G11 2251 D7 2254 E11 2258 G5 2262 D15 2266 B15 3250 A5
1251 E3 2252 D11 2256 A6 2259 G5 2264 C15 2267 E6 3251 A8
1252 I3 2253 E7 2257 B7 2260 H7 2265 D19 2268 F11 3252 H5
1 2 3 4
COMBI BOARD - SUPPLY PART
A
B
C
7.9V ac
8.3V ac
8V ac
T250
D
1251
1
15.8V ac
from Mains
9253
16.6V ac 2
E
Transformer
16.1V ac
3
EH-B
F
T253
G
H
I
1252
T257
1
T258
to 2
+C
Low Power Standby (L.P.S.) T259
3
Transformer
T260
4
STANDBY
J
EH-B
K
L
1 2 3 4
11 - 3
3253 H5 3256 B14 3259 C15 3262 D16 3265 E16 3268 F17 3271 I13 3274 K15
3254 H6 3257 B14 3260 C16 3263 D13 3266 F16 3269 G16 3272 I13 3275 H15
3255 B13 3258 B15 3261 D16 3264 D18 3267 F17 3270 I12 3273 J13 3276 J17
5 6 7 8 9
2256
3250 6266 3251
2K2
470R 22u 1N4148
2257 6268
-8.2V -8.2V
10u BZX79-F8V2
6267
1N4148
6254 6255 6256
2251
9.2V
100n
1N4003 1N4003 1N4003
10.6V 9.8V
T254
+B
2267 2253
6260 6261 6262
3m3
100n
1N4003 1N4003 1N4003
T256
2258 2259
4u7
4u7
Recognition
6269
Mains Breakdown 6.2V
6.2V
1N4148
6270 6.2V
3254
PWRDWN
1N4148
2K2
6271
3252 3253 2260
47n
4K7 4K7
BZX79-F6V8
5 6 7 8 9
3277 K17 3280 K19 3283 C17 6255 D8 6258 D10 6261 E8 6264 E10 6267 B7
3278 J18 3281 C17 3284 C17 6256 D9 6259 D10 6262 E9 6265 E10 6268 B8
3279 K19 3282 C17 6254 D8 6257 D9 6260 E8 6263 E9 6266 A7 6269 G6
10 11 12 13
17.7V
18.4V
-8V2 +A
21V
-8.2V
3255
1K
BC847B
3263
STANDBY
4K7
6258 2252
6257 6259
100n
1N4003
1N4003 1N4003
18.8V
21.7V 19.8V
T255
+A
6263 6265
6264 2254
1N4003 1N4003 100n
1N4003
2268
4m7
PAD
P_GND D_GND A_GND
0250
to
BOTTOM
PLATE
+C
3271
4R7
(no L.P.S.)
3272
9255
+B
4R7
3270 6274
3273
1N4003
3R3
4R7
(L.P.S.) (L.P.S.)
10 11 12 13
11 - 3
6270 H6 6273 F18 7250 A14 7253 C19 7256 I16 7259 J14 9252 B19
6271 H8 6274 I12 7251 C14 7254 E17 7257 I15 7260 J18 9253 E4
6272 B16 6275 J17 7252 C16 7255 G17 7258 J14 7261 K18 9254 E18
14 15 16 17 18
12.2V
BDW94CFP
0V
7250
12.2V
2266
100n
6272
BZX79-F10
3258
47K
3256 3257
2.3V
1K
1K
2.3V
21V
0V
18.4V 3284
17.8V
0V 2K2
7251
0.57V
BC847B 3260
0.57V
3259 7252
220K
2264 330R
0.58V
10u
3262
0V 1K
3261
2262 0.58V
1n 82K
(forseen only)
3265
9.2V
0.4V
1R
BC369
9.8V
7254 T262
9256 9254
+B
3266
6273
47K
1N4003
(forseen only)
8.5V
10.6V
3267 3268
9.2V
2K2 2K2
0.14V
10.6V
0.7V
3269 0.7V 0.14V
STANDBY
7255
22K
0V
BC847B
9.1V
10.6V 9.8V
3275
470R
BC327-25
7256
5.35V
9.1V
BC327-25
10.6V 9.8V 5.5V
7257
5.7V
BC327-25
8.4V
7258 10V 9.3V
9.1V 6275
3276
2K2
10.6V
BZX79-F3V3
9.8V
3278
2.85V 2.8V
2.7V 47K
7259
BC847B
2.35V 2.2V
2.1V
3274 3277
390R 2K2 BC847B
(230V MAINS SUPPLY ) DC VOLTAGES MEASURED IN :
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
14 15 16 17 18
9255 I12 T253 F3 T256 F6 T259 J3 T262 E18
9256 E16 T254 E6 T257 I3 T260 J3 T263 I19
T250 D3 T255 E11 T258 I3 T261 A19 T264 J19
19 20 21
A
T261
+12V BACKLIGHT
ETF_MOTOR (MC148)
9252
+AMP
B
7253
C
BC368
+12V_AF TUNER
ETF_AF
3264
1K
2265
D
100u
E
+CD_MTF_MOTOR
F
G
H
I
T263
+5V6 uP
CD
BC807-25 5.35V
5.5V T264
7260
+5V6_S AF
0.5V RDS
J
ETF_LOGIC
4.8V
5.67V
4.6V
3279
1K
0V
0V 5.67V
3280
7261 K
STANDBY
22K
0.65V
0.65V
0V
L
19 20 21