How
to take out the CD at emergency
1. If power is connected:
- Turn power on.
- Open the tray using the open/close key.
- Remove the Door in the direction of arrow.
2. If power is not connected:
- Turn the gear clockwise using a screw driver as shown in Figure.
- Pull the Tray in the direction of arrow @ and then remove the Door in the direction of arrow.
Tuner adjustment points
Cassette deck adjustments
Test Equipment needed
1. Oscilloscope
2. VTVM
TAPE
1. MTT-111 (or equivalent) : Test tape on which 3KHz signal is recorded (Tape speed adjustment)
2. MTT-5512 (or equivalent)
3. MTT-113CN (or equivalent) : Test tape on which 8KHz signal is recorded (Azimuth)
4. MTT-112B (or equivalent) : Test tape on which 1KHz signal is recorded (L.R. channel unbalance)
Adjustment Procedure
Tracing gain adjustment
Special circuit descriptions
RF Amp (KA9220) : NIC9220
RF I-V Amp(1) and RF I-V Amp(2) currents are converted to voltage via internal resistance of 58k½ from the current of PD1(A+C) and PD2(B+D):
These voltage are added by the RF summing amplifier. The signal (A+B+C+D) is applied to RFO (No. 2 terminal).
RF output voltage is calculated as follows :
VRF= -R3 x (iPD1 + iPD2)
VRF= -R3 x (V1/R1 + V2/R2)
VRF= -R3 x ( + )
VRF= - x (V1 + V2)
FOCUS ERROR Amp(KA9220) : NIC9220
FOCUS ERROR Amp amplifies the difference between RF I-V Amp(1) output (A+C) and RF I-V Amp(2) output(B+D).
These two signals are supplied to (-) and (+) input terminals of FOCUS ERROR Amp. The FOCUS ERROR output is applied to FE (Terminal No.57).
The FE output voltage of this low frequency component varies according to {(A+C) - (B+D)}.
VFE is calculated as follows:
VFE = (R2/R1) x (V2-V1) = 5.4(V2-V1)
This FOCUS ERROR voltage is sent to FOCUS SERVO .
FOCUS SERVO SYSTEM (KA9220) : NIC9220
When FS3 is ON, high frequency gain decreases (time constant set by pin17, pin19 ; capacitor is connected to internal resistance).
The capacitor between pin 18 and GND sets the time constant to pass the low frequencies in PLAY mode.
The maximum frequency of the focus phase compensation is inversely proportional to the resistance connected to pin 7. Focus search peak is about 1.1 Vp-p, and is inversely proportional to the resistance connected to pins 22,23
(if this resistance changes, the peak of track jump and sled kick change).
The inverted input of FZC comparator is set to 5.7% of the difference between Vcc and VC(pin69) {{5.7% x (Vcc-Vc)}.
Note : If the resistance connected to pin7 changes, the phase compensation peak of the focus tracking sled servos change. (The 'op-amp' dynamic range and offset voltage also change.)
TRACKING SLED SERVO SYSTEM (KA9220) : NIC9220
The capacitor between pin 15 and 16 attenuates high frequencies when TG2 is off. The maximum frequency of tracking phase compensation is inversely proportional to the resistance connected to pin 7 (about 1.2kHz at 470k).
The tracking jump (FWD and REV) is determined when TM3 and TM4 are ON, and the peak voltage induced from the tracking coil is determined by both TM3 and TM4 currents and the feed back resistance of pin 47.
Track jump max voltage = TM3 (TM4) current x feedback resistance.
FWD or REV sled kick occurs when TM5 or TM6 is ON, and the peak voltage added to sled motor (determined by TM5 or TM6 current and the feedback resistance of pin 41.)
Sled jump max. voltage = TM5(TM6) current x feedback resistance.
Each SW current is determined by the resistance connected to pin 22 and 23.
When the resistance is about 150½,
TM3 or TM4 = 11µA,
TM5 or TM6 = 22µA,
This current is inversely proportional to the resistor, variable within a range of t 5 to 40 µA for TM3.
STOP is the ON/OFF detection signal for the limit SW (or the sled motor's innermost circumference).
CD Pack Exploded View
Schematic diagram-Main board
Front board schematic
CD board schematic
Video CD board schematic
