Tape Mechanism Electronics; Tape Adjustment & Check Table; Mechanism B Head Wires Soldering (Non-Dolby Version); Mechanism B Head Wires Soldering (Dolby B Nr Version) - Philips FW-C390 Service Manual

TAPE MECHANISM ELECTRONICS

B Photo Sensor
Rec-R
CrO2*
Rec-F
Solenoid
B-Mode
R1 (680R)
Solenoid
Motor
A-Mode
R2 (680R)
A Photo Sensor
CrO2*
* No Leaf switch & copper pattern
shorted together for Ferro version

Mechanism B Head Wires Soldering (Non-Dolby version)

Rec/Pb
Head
For Auto-reverse Head

Mechanism B Head Wires Soldering (Dolby B NR version)

Rec/Pb
Head
For Auto-reverse Head
9-5
1. B Rec Switch (REV)
2. B CrO2 Switch
3. B Rec Switch (FWD)
4. B Photo Out
5. B Solenoid
6. Vcc 12V
7. B Mode Switch
8. Gnd
9. A Solenoid
10. A Photo Out
11. A Mode Switch
12. Motor L
13. A CrO2 Switch
14. Motor H
Mechanism A Head Wires Soldering
Play
Pink or
Head
Red
White
Head wire
connector pcb
Head wire
connector pcb
Rec/Pb
1. +L ch (White)
Head
2. - ch (Black)
3. +R ch (Red)
4. E Head (Blue)
Erase
5. E Head (Yellow)
Head
For Normal Head
Head wire
Head wire
connector pcb
connector pcb
1. +L ch (White) Rec/Pb
2. - L ch (Black) Head
3. +R ch (Red)
4. - R ch (Blue)
5. E Head (Yellow)
Erase
6. E Head (Yellow)
Head
For Normal Head
TAPE ADJUSTMENT & CHECK TABLE
TEST
CASSETTE
ADJUST MOTOR SPEED
SBC420
NORMAL SPEED
3150Hz
CHECK WOW & FLUTTER
SBC420
DECK A & B
3150Hz
ADJUST AZIMUTH
SBC420
DECK A & B
10kHz
CHECK PLAYBACK FREQUENCY RESPONSE
DECK A & B SBC420
ADJUST BIAS CURRENT
SBC419A^
DECK B
SBC420
CHECK OVERALL FREQUENCY RESPONSE AND DISTORTION
Inject 3mV signals
SBC419A^
100Hz, 250Hz, 1kHz,
or
10kHz, 12.5kHz
SBC420
via or 4
3
RECORDED
Screen
CASSETTE
(Gnd)
Inject 1kHz 8.85mV
SBC419A^
or
via or
3 4
SBC420
RECORDED
CASSETTE
1. White
2. Black
3. Red
SBC419A^ : 4822 397 30069
4. Blue
SBC420 : 4822 397 30071
5. Yellow
level(dB)
8dB
1. White
2. Black
3. Red
4. Blue
5. Yellow
80 250
9-5
RECORDER MEASURE
READ ON
ON
MODE
PLAY B
1 or 2
frequency
counter
PLAY A
LEFT RIGHT
or
1 2
PLAY W&F-meter
LEFT RIGHT
PLAY FWD
left hand screw
1 or 2
mV-meter
PLAY REV # right hand screw
LEFT RIGHT
or
1 2
mV-meter
PLAY
LEFT RIGHT
or
5 6
mV-meter
RECORD
LEFT RIGHT
RECORD B
or
1 2
PLAY B mV-meter
LEFT RIGHT
RECORD B
or
1 2
PLAY B THD-meter
LEFT RIGHT
# For Auto-reverse version only
* If high frequencies are not within limits, decrease bias and re-measure.
If distortion is too high, increase bias and re-meaure
^ Not applicable for Ferro version
level(dB)
6dB 8dB 8dB
10dB (HSD)
f(Hz)
4k 12.5k 100
figure. 1
ADJUST
with to
3620
3150Hz +/- 0.5%
check 3150Hz -0.8/+1.8%
check
<0.4 % DIN
max. output level
& left=right
check
limits see fig.1
3773 995mV
check
750mV +/- 1.5dB
limits see fig. 2 *
check
check <3% *
6dB 8dB
10dB (HSD)
f(Hz)
250 4k 10k
figure. 2