Hitachi CP 90 S Service Manual

Page 2

CP-QOS/CP-QOOS I

SAFETY PRECAUTIONS

The following precautions should be observed when servicing.

1. Since many parts in the unit have special safety-related characteristics, always use genuine Hitachi's replacement
parts. Especially critical parts in the power circuit block should not be replaced with other makes.
Critical parts are marked with & in the schematic diagram and circuit board diagram.

2. Before returning a repaired unit to the customer, the service technician must thoroughly test the unit to ascertain
that it is completely safe to operate without danger of electrical shock.

3. Before returning a repaired unit to the customer, the service technician must measure the leakage-current or resist-
ance to determine that the exposed parts are acceptably insulated from the power circuit.

CONTENTS
CRQOS/CP-QOOS SYSTEM COMPONENTS ......................................... 3
DIFFERENCES BETWEEN CP-QOS AND CRQOOS .................................... 3
SYSTEM CONNECTION AND CIRCUIT OPERATION ................................. 4
1. CP-QOS ............................................................. 4
2. CRQOOS ............................................................ 7
DESCRIPTION OF NEW CIRCUIT .............................................. 10
1. SBBS (Super Bass Boost System) circuit (CP-QOS/CP-QOOS) .......................... 10
2. AC-DC combination erase head (CP-QODEX) .................................... 11
CAUTIONSON REPAIRING PRINTED RESISTOR .................................. 11
TUNER CP~90THITE/TW .................................................... 13
STER EO AMPLIFIER CP-QOS/QOOS, SYSTEM RACK CP-90R EX, SPEAKER CP-QOSP ............ 33
STEREO CASSETTE RECORDER CRQODEX ...................................... 55
DOLBY/GRAPHIC EOUALIZER CP-QIEO ................................ . ......... 69
STEREO CASSETTE PLAYER CP-QIDEX ...... . ................................... 77

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l CP-90DEX

CP-90DEX

STEREO CASSETTE RECORDER

KEY TO IL LUSTRATIONS

OPERATION BUTTONS
TAPE COUNTER

TONE SWITCH
VOLUME CONTROL
HEADPHONE SOCKETS
MICROPHONE SOCKET
RIF SWITCH

PAUSE SWITCH

TAPE SELECT SWITCH
OPERATION/BATTERY INDICATOR
RECORD BUTTON

5ri

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SPECIFICATIONS

Tape: Cassette tape (C-30, 60, 90) Input Sensitivity and

Track SWIM": 4 "30k 2 CharHEI Impedance: Microphone: 0.3 mV, 3.3k ohms
Tape Speed: 4.75 em/s Output Impedance: Headphone: 8 ohms to 300 ohms
Recording System: AC Bias, 57 kHz Wow and Flutter: 0.2% (WRMS)

Erasing System: AC erase Fast Forward or

Frequency Response:

Metal: 50 to 14,000 Hz

Rewinding Time:

120 sec. (Using C-GO)

Normal: 50 to 12,000 Hi Semiconductors: le: 4
S/N (Signal to Noise Transistors: 9
Ratio): 50 dB Diode: 2
Distortion: 2% LED: 1
Motor: DC micrometer Power Output: 30 mW +30 mW (T.H.D. 10%)
Cross Talk: 50 dB (Between tracks) Power Supply: DC 3V (AA" cell X 2 or IE0 R6 x 2)
30 dB (Between channels) Power Consumption: 160 mA (with no signal)
Erase Ratio: 50 dB Dimensions: 120(W) x 33.5(H) x 80(0) mm
Weight: 3209 (with batteries)
ODNNECTORS
System CP-9OS/CP-9OOS
Connector Terminal Input/Output
1 R signal input/output
2 L signal input/output
3 GND
PHONES A PHONES B 8P pin 4 +3V power input
Connector 5 REC +3
6
DC IN 3V 7 Motor GND
[ 8 Motor +B
Independently
@ MIC MIC input
H t t
PHONES A eadphone ou pu
| 2 3 4 5 5 7 g B Headphone output
DC IN 3V +3V power input

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