4-5
CCP-1100SF
4-2-5. Bias trap adjustment
Test equipment :
Level meter
Adjustment point : FL1, FL2/AU-2 board
Procedure :
1.
Set the SIDE selector to “A
+
B”.
2.
Activate the service mode. (Don't insert a cassette tape.)
3.
Press the COPY button, connect the level meter to the
following test point on the AU-2 board.
4.
Adjust the bias trap associated with the test point so
that the output becomes the minimum.
CH
Level meter connection
Adjustment
+
+
+
+
+
terminal
_
_
_
_
_
terminal
point
CH-1
TP3
E3
FL1
CH-2
TP4
E4
FL2
AU-2 Board Component Side
E3
TP3
TP4
E4
FL1
FL2
4-2-6. Bias current pre-adjustment
Test equipment :
Voltmeter
Adjustment point : CT1, CT2/AU-2 board
Procedure :
1.
Active the service mode. (Don't insert a cassette tape.)
2.
Press the COPY button, connect the voltmeter to the
following test points on the AU-2 board.
3.
Adjust the trimmer capacitor associated with the test
point so that the output becomes 40
±
3 mV
CH
Voltmeter connection
Adjustment
+
+
+
+
+
terminal
_
_
_
_
_
terminal
point
CH-1
TP106
E107
CT1
CH-2
TP107
E107
CT2
AU-2 Board Component Side
TP107
TP106
E107
CT1
CT2
4-2-7. Erase head dummy coil adjustment
Note : Before this adjustment, the bias current pre-adjustment must has
been finished.
Test equipment :
Voltmeter
Frequency counter
Coil (10 mH)
Adjustment point : L4/AU-2 board
Procedure :
1.
Set the SIDE selector to “A
+
B”.
2.
Activate the service mode. (Don't insert a cassette tape.)
3.
Press the COPY button.
4.
Connect the voltmeter to test point TP106 on the AU-2
board. and measure the voltage.
Specification : 40
±
3 mV
(If out of the specification, again adjust the bias
current pre-adjustment.)
5.
Connect the coil to the frequency counter.
6.
Make the coil approach to erase head to check that the
bias frequency is in specification.
Specification : 550 kHz
±
3 %
(If out of the specification, again adjust the bias
frequency.)
7.
Next, set the SIDE selector to the “A”, and measure
the voltage at the test point TP106.
Then, adjust the dummy coil L4 so that the difference
between the measured voltage and that when the SIDE
selector was in “A
+
B” status is within 3 mV in the
rang of 40
±
3 mV.
8.
Again, make the coil approach to the erase head, and
adjust the bias transformer so that difference between
the measured bias frequency and that when the SIDE
selector was in “A
+
B” status is within 16 kHz in the
range of 550 kHz
±
3 %.
Voltmeter Connection
Adjustment
+
+
+
+
+
terminal
_
_
_
_
_
terminal
point
TP106
E107
L4
AU-2 Board Component Side
E107
L4
TP106
