Philips MC-M250 - System Maintenance; Cleaning Procedures; Demagnetizing Tape Heads; Troubleshooting Common Issues

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AM FRAME AERIAL
FM 75‰
FM FRONTEND
Birdy Filter
ECO6 Sys-Cenelec, layout stage .5, 080900
1101 B5
1102 B5
1103 C5
1110 B4
1120 A4
1130 A5
1131 C5
1132 A4
2106 B4
2107 B3
2128 A3
2129 B3
2133 C1
2138 B1
2144 B1
2162 A4
2191 B4
3142 C2
5102 C4
5103 C4
5109 B3
5110 A2
5111 A3
5112 A2
5114 A2
5115 C2
5119 B2
5121 B2
5122 C3
5123 C3
7104 C4
7105 C5
7112 B1
9101 A2
9102 B2
9103 A1
9104 B1
9105 B1
9106 B1
9107 B4
9108 B3
9109 C2
9110 A4
9111 A3
TUNER BOARD ECO6 Systems - Cenelec / componentside view
B
A
LAYOUT DIAGRAM - ECO6 SYSTEM CENELEC BOARD
These assembly drawings show a summary of all possible versions.
For components used in a specific version see schematic diagram respectively partslist.
ECO6 Sys-Cenelec, layout stage .5, 080900
41..
in schematic diagram)
(not all items shown
SMD jumper
EB
C
A
K
TUNER BOARD ECO6 Systems - Cenelec / copperside view
2102 B1
2105 B1
2108 C1
2109 C1
2118 C3
2119 C3
2120 C3
2122 C3
2123 C3
2124 C3
2125 C3
2127 C4
2130 B3
2131 C4
2132 C4
2134 C4
2135 C5
2136 A3
2137 A3
2139 B4
2140 B4
2141 B5
2143 B5
2145 B5
2146 B5
2147 A5
2148 B4
2149 C4
2150 B3
2159 B3
2161 A4
2163 A4
2164 B4
2165 B3
2166 B5
2167 B4
2169 A3
2190 B2
3105 B3
3108 C2
3109 C1
3123 A5
3125 A5
3128 C2
3132 B3
3134 C3
3137 C4
3141 B3
3143 C5
3144 A5
3145 C4
3146 B5
3150 B3
3151 A2
3152 A3
3153 A3
3154 B5
3155 B5
3156 A4
3157 A4
3158 A3
3159 A3
3160 A3
3161 A4
3167 A5
3168 C5
3169 B4
3170 A4
3171 B5
3172 B5
3176 C4
3180 A5
3190 B2
3191 A3
3192 A2
3193 B2
3194 B2
3195 B2
4101 C2
4102 C2
4104 C3
4105 B2
4106 B3
4107 C4
6105 B2
6106 B2
6107 B5
6120 A4
7101 B4
7103 C5
7109 A5
7110 B2
7111 A4
7122 C3
7124 C3
1
1
8
2
7
8
4
D
A
C
1 25
3
V
dd
Vcc2
Vcc1
+FM
98MHz
Waverange Input frequency Input Tuned to Adjust Output Scope/Voltmeter
VARICAP ALIGNMENT
FM - VCO
FM RF (channel separation)
AM IF
AM RF
3)
108MHz
87.5MHz
check
check
8V ±1.2V
1.6V ±0.5V
8V ±0.2V
6.9V ±0.2V
1.1V ±0.4V
152kHz ±1kHz
1)
98MHz 3142
198kHz198kHz 5103
5111
FM
87.5 - 108MHz
(50kHz grid)
1602kHz
531kHz
5123
check
MW
531 - 1602kHz
(9kHz grid)
8V ±0.2V
1.1V ±0.4V
279kHz
153kHz
5122
check
LW
153 - 279kHz
(3kHz grid)
FM
FM
LW
558kHz558kHz
1494kHz
5102
1494kHz 2106
MW
MW
98MHz, 1mV
continuous wave
98MHz, 1mV
90% Left + 9% pilot
mod=1kHz
IF coil
inside
FM
frontend 
1110
1
3
5
5
A
FM - IF
0mV ±3mV5119
FM
10.7MHz, 45mV
continuous wave
2D
right channel min.
4A
0mV ±2mV5114
2
C
Repeat
C
5112
1)
If sensitivity of frequency counter is too low adjust to max. channel separation
(input signal: stereo left 90% + 9%, adjust output on right channel to minimum)
2)
RC network serves for damping the IF-filter while adjusting the other one.
3)
For AM RF adjustments the original frame antenna has to be used!
TUNER ADJUSTMENT TABLE ( ECO6 Cenelec FM/MW - and FM/MW/LW - versions with AM-frame aerial )
max.
symmetric
f
o
max.
symmetric
f
o
ECO6 Sys Cenelec, 190599
B
∆f = ±30kHz
V
RF
as low as
possible
MW has to be aligned before LW.

3-band
2-band
Note:The FM-frontend unit has already been adjusted by the factory
 and needs therefore no further adjustments for service purposes.
2141
shortcircuit
to block AFC
21
IC 7101
see 
remark
2)
220R
100nF
36
IC 7101
220R
100nF
40
IC 7101
450kHz

connect pin 6 of
IC 7101 (AM Osc.)
with 3.3kΩ to Vcc
AM AFC
MW
continuous wave
V
RF
= 2mV
∆f = ±10kHz
V
RF
= 0.5mV
(as low as
possible)
Use Service Testprogram. By selecting the TUNER TEST test frequencies will be stored as preset frequencies automatically.
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