Read Sony CMT-EH45DAB / HCD-EH45DAB Service Manual online
HCD-EH45DAB
11
Adjustment Location: Record/Playback/Erase Head
Note: Remove the cassette lid before this adjustment.
Refer to “DISASSEMBLY” (page 6)
TUNER SECTION
FM TUNE LEVEL CHECK
signal
generator
set
Procedure:
1. Turn on the set.
2. Input the following signal from signal generator to FM antenna
1. Turn on the set.
2. Input the following signal from signal generator to FM antenna
input directly.
Carrier frequency : A = 87.5 MHz, B = 98 MHz, C = 108 MHz
Deviation
Deviation
:75 kHz
Modulation
: 1 kHz
ANT input
: 35 dBu (EMF)
Note: Use 75 ohm coaxial cable to connect signal generator and the set.
You cannot use video cable for checking.
Use signal generator whose output impedance is 75 ohm.
3. Set to FM tuner function and tune A, B and C signals.
4. Confi rm “TUNED” is lit on the display for A, B and C sig-
4. Confi rm “TUNED” is lit on the display for A, B and C sig-
nals.
When the selected station signal is received in good condition,
“TUNED” is displayed.
“TUNED” is displayed.
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjust-
ment.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicat-
ed.
3. Use an oscilloscope with more than 10 M
Ω impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specifi ed value with the fol-
lowing checks.
lowing checks.
5. Check the focus bias check when optical pick-up block is re-
placed.
FOCUS BIAS CHECK
+
–
–
CD board
TP122 (RFEQO)
TP124 (VC)
oscilloscope
(DC range)
Procedure:
1. Connect oscilloscope to TP122 (RFEQO) and TP124 (VC) on
1. Connect oscilloscope to TP122 (RFEQO) and TP124 (VC) on
the CD board.
2. Press the [
?
/
1
] button to turn the power on.
3. Set the disc (YEDS-18) and press the [CD
u
] button to play-
back.
4. Confi rm that oscilloscope waveform is as shown in the fi gure
below. (eye pattern)
A good eye pattern means that the diamond shape (
◊) in the
center of the waveform can be clearly distinguished.
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.2 ± 0.3 Vp-p
Checking Location:
TP124
(VC)
– CD Board (Conductor Side) –
TP122
(RFEQO)
IC101
Click on the first or last page to see other CMT-EH45DAB / HCD-EH45DAB service manuals if exist.