Sharp GX-CH170X User manual

GX-CH170X/CH170Z
No. S6631GXCH170Z
SERVICE MANUAL
CONTENTS Page
SPECIFICATIONS ............................................................................................................................................................. 2
VOLTAGE SELECTION (GX-CH170Z ONLY)................................................................................................................... 2
NAMES OF PARTS ........................................................................................................................................................... 3
REMOTE CONTROL ......................................................................................................................................................... 4
DISASSEMBLY.................................................................................................................................................................. 5
REMOVING AND REINSTALLING THE MAIN PARTS..................................................................................................... 7
FITTING OF DIAL POINTER ............................................................................................................................................. 8
ADJUSTMENT ................................................................................................................................................................... 9
TROUBLESHOOTING (CHANGER/CD SECTION) ........................................................................................................ 11
NOTES ON SCHEMATIC DIAGRAM .............................................................................................................................. 16
TYPES OF TRANSISTOR AND LED............................................................................................................................... 16
BLOCK DIAGRAM ........................................................................................................................................................... 17
SCHEMATIC DIAGRAM / WIRING SIDE OF P.W.BOARD............................................................................................. 20
WAVEFORMS OF CD CIRCUIT...................................................................................................................................... 35
FUNCTION TABLE OF IC................................................................................................................................................ 36
LCD SEGMENT ............................................................................................................................................................... 37
PARTS GUIDE/EXPLODED VIEW
DIFFERENCE BETWEEN GX-CH170X AND GX-CH170Z
GX-CH170X GX-CH170Z
TUNER 2 BAND 4 BAND
FINE TUNING
FM STEREO INDICATOR
POWER SOURCE AC 220-240 V,50 Hz AC 110-127/220-240 V,
50/60 Hz
GX-CH170X
GX-CH170Z
• In the interests of user-safety the set should be restored to its
original condition and only parts identical to those specified
should be used.
SHARP CORPORATION
Illustration: GX-CH170Z

GX-CH170X/CH170Z
FOR A COMPLETE DESCRIPTION OF THE OPERATION OF THIS UNIT, PLEASE REFER
TO THE OPERATION MANUAL.
SPECIFICATIONS
General
Power source: AC 220-240 V, 50 Hz
(GX-CH170X) DC 12 V [ "D" size (UM/SUM-1,
R20 or HP-2) battery x 8]
Power source: AC 110-127/220-240 V, 50/60 Hz
(GX-CH170Z) DC 12 V [ "D" size (UM/SUM-1,
R20 or HP-2) battery x 8]
Power consumption: 55 W
Output power: PMPO; 60 W (total)
MPO (Max.); 24 W (12 W + 12 W)
(AC operation)
RMS; 10 W (5 W + 5 W)
(DC operation, 10 % T.H.D.)
Output terminal: Headphones; 16 - 50 ohms
(recommended; 32 ohms)
Dimensions: Width; 290 mm (11-1/2")
Height; 260 mm (10-1/4")
Depth; 277 mm (10-15/16")
Weight: 4.3 kg (9.5 Ibs.) without batteries
Compact disc player
Type: Twin CD mechanism
Signal readout: Non-contact, 3-beam semi-
conductor laser pickup
Audio channels: 2
D/A converter: 1-bit D/A converter
Decoder: 16-bit linear quantization
Filter: 4-tims oversampling digital filter
Wow and flutter: Unmeasurable
(less than 0.001% W. peak)
Radio
Frequency range: FM; 87.6 - 108 MHz
(GX-CH170X) AM; 530 - 1,702 kHz
Frequency range: FM; 88 - 108 MHz
(GX-CH170Z) MW; 526.5 - 1,606.5 kHz
SW1; 2.3 - 7.3 MHz
SW2; 7.3 - 22 MHz
Tape recorder
Frequency response: 50 - 14,000 Hz (Normal tape)
Signal/noise ratio: 50 dB (TAPE 1, recording /
playback)
55 dB (TAPE 2, playback)
Wow and flitter: 0.25 % (WRMS)
Motor: DC 12 V electric governor
Bias system: AC bias
Erase system: AC erase
Speaker section
Type: 2-way 4-speaker bass-reflex type
Speakers: 10 cm (4") woofer x 2
Tweeter x 2
Maximum input power: 8 W
Impedance: 3.2 ohms
Dimensions: Width; 190 mm (7-1/2")
Height; 260 mm (10-1/4")
Depth; 183 mm (7-1/4")
Weight: 1.3 kg (2.9 Ibs.) /each
– 2 –
92LCoRD577BQACCB0004AW00
QACCE0007AW00 92LPLUG027 92LPLUG155A
Figure 2 AC POWER SUPPLY CORD AND AC PLUG ADAPTOR
Before operating the unit on mains, check the preset voltage.
If the voltage is different from your local voltage. Slide the AC
powersupplysocketcoverbyslightlyloosingthescrewtothe
visible indication of the side of your local voltage.
VOLTAGE SELECTION (GX-CH170Z ONLY)
Specifications for this model are subject to change without
prior notice.

GX-CH170X/CH170Z
Main unit (Illustration: GX-CH170Z)
1. Disc Number Indicator
2. Random Indicator
3. CD Play Indicator:
4. Track Number/Minutes and Seconds/Volume Level/
Programme Number Indicator
5. Programme Indicator
6. CD Repeat Indicator:
7. (DISC 1) Open/Close Button:
8. (DISC 1) Indicator
9. (DISC 1) Disc Tray
10. Random Play Button
11. Clear Button
12. Programme Button
13. (DISC 2) Indicator
14. (DISC 2) Open/Close Button:
15. (DISC 2) Disc Tray
16. DISC 1 2 Select Button
17. (CD) Play/Repeat Button:
18. (CD) Stop Button:
19. (CD) Pause Button:
20. (CD) Track Up/Cue Button:
21. (CD) Track Down/Review Button:
22. Remote Control Sensor
23. Extra Bass Control: X-BASS
24. Graphic Equalizer Controls
25. Stand-By Indicator
26. Tuning Control
27. Power Button
28. Volume Up/Down Button:
29. FM Stereo Indicator (GX-CH170Z ONLY)
30. Dubbing Speed/Beat Cancel Switch
31. Band Selector Switch (GX-CH170X)
31. Tape Selector/FM Mode Switch (GX-CH170Z)
32. Function Selector/Remote Control Switch
33. Band Selector Switch (GX-CH170Z ONLY)
34. Fine Tuning Control (GX-CH170Z ONLY)
35. (TAPE 1) Cassette Compartment
36. (TAPE 1) Record Button:
37. (TAPE 1) Play Button:
38. (TAPE 1) Rewind Button:
39. (TAPE 1) Fast Forward Button:
40. (TAPE 1) Stop/Eject Button: /
41. (TAPE 2) Play Button:
42. (TAPE 2) Stop/Eject Button: /
43. (TAPE2) Cassette Compartment
– 3 –
Rear panel
44. FM Telescopic Rod Aerial (GX-CH170X)
44. FM/SW Telescopic Rod Aerial (GX-CH170Z)
45. Headphone Socket
46. Speaker Terminals
47. Battery Compartment
48. AC Power Input Socket
49. AC Voltage Selector (GX-CH170Z ONLY)
NAMES OF PARTS
1
2
RANDOM
VOLUME
PROGRAM
34
1
265
1011 12 13
98
22 212019 18 17
714
16
15
30
383736 3940 41 4235 43
23
31 32 33 34
24 25 26 27
28
29
44
45
46
48 49
47

GX-CH170X/CH170Z
– 4 –
Speaker section
1. Tweeter
2. Woofer
3. Bass Reflex Port
4. Speaker Wire
Remote Control
5. Remote Control Transmitter LED
6. Power Button
7. Track Down/Review Button:
8. Pause Button:
9. Random Button
10. Play/Repeat Button:
11. DISC 1 2 Select Button
12. Track Up/Cue Button:
13. Stop Button:
14. Programme Button
15. Volume Up/Down Buttons:
REMOTE CONTROL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
(Illustration: GX-CH170X)
25˚ 25˚
0.3 m - 6 m
(12" - 20')
Notes concerning use:
Replace the batteries if control distance decreases or oper-
ation becomes erratic.
Periodically clean the transmitter LED on the remote control
and the sensor on the main unit with a soft cloth.
Exposing the sensor on the main unit to strong light may in-
terfere with operation. Change the lighting or the direction of
the unit.
Keep the remote control away from moisture, excessive heat,
shock, and vibrations.

GX-CH170X/CH170Z
UNIT
1 Front Cabinet 1. Screw..................(A1) x11 5-1
2. Socket...................(A2) x1 5-2
3. Tip.........................(A3) x1 6-5
2 CD Block 1. Screw....................(B1) x2 5-2
2. Socket...................(B2) x3 5-3
3 Graphic EQ. PWB 1. Screw................... (C1) x3 5-3
2. Socket.................. (C2) x1
4 Tuner PWB 1. Screw................... (D1) x2 5-3
(with Tuner Frame) 2. Flat Cable .............(D2) x1
5 Main PWB 1. Hook .....................(E1) x1 5-3
2. Flat Cable............. (E2) x3 5-3,6-1
6 Display PWB/ 1. Screw.................... (F1) x9 5-3,6-1
Switch PWB 2. Hook ..................... (F2) x1 6-1
7 Deck PWB 1. Screw................... (G1) x3 6-1
2. Socket.................. (G2) x3
8 Tape Mechanism 1. Open the cassette holder.
2. Screw................... (H1) x6 6-2
9 CD Servo PWB 1. Screw.................... (J1) x2 6-3
10 CD Mechanism 1. Screw....................(K1) x6 6-4
11 Power PWB/ 1. Open the battery lid.
Terminal PWB 2. Screw.................... (L1) x4 6-5
3. Hook ..................... (L2) x1
SPEAKER
1 Front Panel 1. Screw .................. (N1) x4 6-6
DISASSEMBLY
Caution on Disassembly
Followthe below-mentioned notes when disassembling the
unitandreassemblingit,tokeepitsafeandensureexcellent
performance:
1. Take cassette tape and compact disc out of the unit.
2. Be sure to remove the power supply plug from the wall
outlet before starting to disassemble the unit.
3. Take off nylon bands or wire holders where they need be
removedwhendisassemblingtheunit.Afterservicingthe
unit, be sure to rearrange the leads where they were
before disassembling.
4. Take suffcient care on static electricity of integrated
circuits and other circuits when servicing.
STEP REMOVAL PROCEDURE FIGURE
Figure 5-3
Figure 5-1
– 5 –
( A1 ) x2
ø3 x6mm
( A1 ) x2
ø3 x6mm
( A1 ) x2
ø3 x10mm
( A1 ) x4
ø3 x20mm
( A1 ) x1
ø3 x65mm
Rear
Cabinet
Front
Cabinet
Front
Cabinet
CD Block
Main PWB
( B1 ) x1
ø3 x10mm
( B1 ) x1
ø3 x10mm
( A2 ) x1
Figure 5-2
Front
Cabinet
Switch
PWB
Graphic EQ. PWB
Switch
PWB
Tuner
PWB
Main PWB
( C2 ) x1
( E2 ) x1
( B2 ) x3
( D2 ) x1
( E1 ) x1
( F1 ) x2
ø3 x10mm
( F1 ) x2
ø3 x10mm
( D1 ) x1
ø3 x10mm
( D1 ) x1
ø3 x10mm
( C1 ) x3
ø3 x10mm

GX-CH170X/CH170Z
Figure 6-1
Figure 6-2
Figure 6-3 Figure 6-6
– 6 –
Figure 6-5
Figure 6-4
( G2 ) x2
( G2 ) x1
( F2 ) x1
( E2 ) x2
Front
Cabinet
Deck
PWB
Tape
Mechanism
Display
PWB
( F1 ) x5
ø3 x10mm
( G1 ) x3
ø3 x10mm
Tape
Mechanism
Front
Cabinet
( H1 ) x6
ø3 x10mm
( J1 ) x2
ø3 x10mm
CD Block
CD Servo
PWB
CD
Mechanism
( K1 ) x1
ø2.6 x8mm
( K1 ) x2
ø2.6 x8mm ( K1 ) x3
ø2.6 x10mm
CD Block
Power PWB
Terminal PWB
( A3 ) x1
( L1 ) x3
ø3 x10mm
( L1 ) x1
ø3 x10mm
Rear Cabinet
Driver
Push( L2 ) x1
Washer
( N1 ) x4
ø3 x20mm
Front Panel

GX-CH170X/CH170Z
B
How to remove the record/playback and erase
heads (TAPE 1) (See Fig. 7-1.)
1. Carefully bend the record/playback head pawls (A1) x 2
pcs.,inthedirectionofthearrow ,andremovetherecord/
playback head upwards.
2.Removethescrews(B1)x2pcs.,toremovetheerasehead.
REMOVING AND REINSTALLING THE MAIN PARTS
Figure 7-6
Figure 7-5
Figure 7-2
Figure 7-3
– 7 –
Figure 7-4
TAPE MECHANISM SECTION
Performsteps1, 2,3,4,5,7 and8ofthe disassemblymethod
to remove the tape mechanism.
How to remove the playback head (TAPE 2)
(See Fig. 7-2.)
1.Carefullybendtheplaybackheadpawls(C1)x2pcs.,inthe
direction of the arrow , and remove the playback head
upwards.
How to remove the pinch roller (TAPE 1/2)
(See Fig. 7-3.)
1. Carefully bend the pinch roller pawl in the direction of the
arrow , and remove the pinch roller (D1) upwards.
How to remove the belt (TAPE 1) (See Fig. 7-4.)
1. Remove the main belt (E1) x 1 pc., from the motor side.
2. Remove the FF/REW belt (E2) x 1 pc.
How to remove the belt (TAPE 2) (See Fig. 7-4.)
1. Remove the tape 2 main belt (E1) x 1pc., from the motor
side.
2. Remove the tape 1 main belt (F1) x 1pc., from the motor
side.
How to remove the motor
(See Figs. 7-5 and 7-6.)
1. Remove the belt.
2. Remove the screws (G1) x 4 pcs., to remove the motor
fixtire.
3. Remove the screws (G2) x 2 pcs., to remove the motor.
Note:
Whenmountingthemotor,payattentiontothemotormounting
angle.
Play Button
TAPE 1
Erase Head Record/Playback
Head
Pawl
(A1)x2
( B1 ) x2
ø2 x7mm
AA
Pinch Roller
(D1) x 1
Pawl C
Pawl
(C1)x2
Play Button
Playback Head
BB
TAPE 2
Figure 7-1
TAPE1
Main Belt
(E1)x1
TAPE2
Main Belt
(F1)x1
Main Belt
(F1)x1 Main Belt
(E1)x1
FF/REW Belt
(E2)x1
Flywheel
Flywheel
Motor
Motor
TAPE 1
TAPE 2
( G1 ) x2
ø2 x4mm
( G1 ) x2
ø2 x4mm
Motor
Bracket
Motor
TAPE2 TAPE1
( G2 ) x2
ø2.6 x2mm
Motor
Bracket
Motor
A
C

GX-CH170X/CH170Z
A
CD MECHANISM SECTION
Perform steps 1, 2, 9 and 10 of the disassembly method to
remove the CD mechanism.
How to remove the pickup (See Fig. 8-1.)
1. Remove the screws (A1) x2 pcs., to remove the shaft (A2) x
1 pc.
2. Remove the stop washer (A3) x1 pc., to remove the gear
(A4) x 1 pc.
3. Remove the pickup.
– 8 –
Figure 8-1
FITTING OF DIAL POINTER
1. Remove the three screws, and remove the tuner PWB from the tuner frame. (See Fig. 8-2) [GX-CH170X]
1. Remove the four screws, and remove the tuner PWB from the tuner frame. (See Fig. 8-2) [GX-CH170Z]
2. Turn fully the dial wheel in the direction. (See Fig. 8-3)
3. Set the dial pointer as shown in Figure 9-2, and mount the tuner PWB.
(GX-CH170X)
Figure 8-2 Figure 8-3
(GX-CH170Z)
(A1) x2
2.6 x6mm
Stop Washer
(A3) x1
CD Mechanism
Gear
(A4) x1
Shaft
(A2) x1
Pickup
Tuner PWB
(Top view)
Screw x3
"0" Point Dial
Pointer
( 235 )
Tuner
Frame
Tuner PWB
(Top view)
Screw x4
"0" Point Dial
Pointer
( 235 )
Tuner PWB
(Bottom view)
A
Tuner PWB
(Bottom view)
A

GX-CH170X/CH170Z
MTT-118 1.8 V ±3 dB Speaker Terminal
(Load resistance: 6 ohms)
PLAY: TW-2412 Tape 1: Over 50 g
Tape 2: Over 100 g
MECHANISM SECTION
• Driving Force Check
Torque Meter Specified Value
TUNER SECTION
fL: Low-range frequency
fH: High-range frequency
• FM IF/RF
Test Stage Specified
Value/Adjusting Point Instrument Connection
Figure 9-2 ADJUSTMENT POINTS
– 9 –
ADJUSTMENT
• Torque Check
Specified Value
Play: TW-2111 30 to 60 g.cm 30 to 60 g.cm
Fast Forward: TW-2231 80 to 135 g.cm
Rewind: TW-2231 80 to 135 g.cm
Tape 1 Tape 2
Torque Meter
• Tape Speed
Nomal MTT-111 VR391 3,000 Speaker
speed ±30 Hz terminal
(Load resistance:
6 ohms)
Instrument
Connection
Specified
Value
Test Tape Adjusting
Parts
TAPE SECTION
Position of each switch or control
Volume control Max
Beat cancel A
Function/Power switch Tape/Off
• Bias Oscillation Check
Beat cancel A: 82 + 10 kHz / -6 kHz
B: -2 ±2 kHz -4 -9
C: +3 ±2 kHz 0 +1.5
Specified Value
IF T1
Detection T2
Band Coverage 87.4 MHz (fL): L2
108.2 MHz (fH): TC2
Tracking 88.0 MHz (fL): L1
108.0 MHz (fH): TC1
Input: Pin 1 of IC1
Output: Pin 17 of IC2
Iuput: Antenna
Output: Headphones
Socket (Load
resistance: 32 ohms)
Test Stage Specified
Value/Adjusting Point Instrument
Connection
• AM IF/RF
IF T3
AM Band Coverage fL: L4 (510 kHz)
(GX-CH170X) fH: TC4 (1,750 kHz)
MWBand Coverage fL: L5 (510 kHz)
(GX-CH170Z) fH: TC6 (1,650 kHz)
SW1 Band Coverage fL: L4 (2.25 MHz)
(GX-CH170Z) fH:TC4 (7.4 MHz)
SW2 Band Coverage fL: L7 (7.2 MHz)
(GX-CH170Z) fH: TC8 (22.5 MHz)
AM Tracking 600 kHz: L3
(GX-CH170X) 1,400 kHz: TC3
MW Tracking 600 kHz: L3 (MW)
(GX-CH170Z) 1,400 kHz: TC5
SW1 Tracking 2.6 MHz: L3 (SW1)
(GX-CH170Z) 6.0 MHz: TC3
SW2 Tracking 8.5 MHz: L6
(GX-CH170Z) 19 MHz: TC7
Input: Antenna
Output: Pin 19 of IC2
Input: Antenna
Output: Headphones
Socket (Load
resistance: 32 ohms)
• VCO Frequency
VR1 76 kHz ±200 Hz Pin 13, pin 21 and
ground of IC2
Specified
Value Instrument
Connection
Adjusting Point
Note:
After preparing the test circuit shown in Fig. 9-1, connect the Pin 13,
Pin 21 and ground of the IC2 with the test circuit, and measure the
value. At this time, apply a standard unmodulated signal input and
adjust the VCO.
Pin 13 of IC2 Pin 21 of IC2
D
G
S
10 kohm
TO FREQUENCY
COUNTER
FET : 2SK19 or 2SK54
Figure 9-1 VCO FREQUENCY TEST CIRCUIT
(GX-CH170X) (GX-CH170Z)
AM TRACKING
fH AM BANDfH
fL COVERAGE
FM
AM TRACKING fL
AM BAR ANTENNA
fH
fL
TRACKING
FM BANDfL
fH COVERAGE
VCO
L4
VR1
TC4
TC3
TC1
1
TC2
L2
L1
L3
T2
T1 T3
FM DET
AM IF
FM IF
FM RF IC2
IC1
13
1
17
19
21
TC8
TC6
VR1
T2 L4
L2
TC5
MW/SW1 BAR ANTENNA
TC7
SW1 TRACKING fH
L5
L6
TC3
TC1
TC2 TC4
L1
L3
L7
T3
T1
IC1
IC2
VCO
FM DET
SW1 TRACKING fLMW TRACKING fL
MW TRACKING fH
fH SW2
fL TRACKING
FM fL
TRACKING fH
FM BAND fH
COVERAGE fL
fH SW1 BAND
fL COVERAGE
fL MW BAND
fH COVERAGE
fL SW2 BAND
fH COVERAGE
FM IF
AM IF
1
1
21
13
17
19
XZ
• Erase Current Check
Specified Value
Resistor for measurement: 1 ohm 50 ±15 mV
• Playback Amplifier Sensitivity Check
Test Tape Specified Value Instrument Connection

GX-CH170X/CH170Z
CD SECTION
Since this CD system incorporates the following automatic
adjustmentfunction,whenthepickupisreplaced,itisnecessary
to reajust it.
Sincethis CDunitdoesnotneedadjustment,thecombination
of PWB and laser pickup unit is not restricted.
– 10 –
TEST MODE
After setting the FUNCTION switch to "CD" turn on power. Not later than 1s but later than 500 msec after power is
turned on press simultaneously the following buttons.
1. CD TEST mode DISC1/2 + DOWN/REVIEW
2. LCD TEST mode DISC1/2 + UP/CUE
3. ELECTRONIC VOLUME TEST mode DISC1/2 + STOP
Start
Note 1. When the CD LID switch is in the OFF position, the unit will be able to enter the test mode.
However, playback cannot be performed in this mode.
2. The LCD lights wholly.
1
2When the "PLAY" button is pressed, the laser will be lit, and when the "STOP" button is pressed, it will be
turned off. Playback will also start and stop when these buttons are pressed.
Turning the tracking servo on or off.3
a. If the "PLAY" button is pressed while in the stop mode, the laser will simply be turned on at first.
b. If the laser is lit and the "PLAY" button is pressed again, playback will start from the current pickup position.
c. If the "STOP" button is pressed, playback will stop. When pressed again, the laser will be turned off.
a. Each time the PAUSE button is pressed during playback, the tracking servo will be turned on or off.
(Note: If the PLAY button is pressed while in the stop mode, the tracking servo will automatically be
turned on.)
Operation The use of the "UP/CUE" button will move the pickup to the outermost position.
The use of the "DOWN/REVIEW" button will move the pickup to the innermost position.
When the TEST mode is entered, at first the CD mechanism is shifted to Tray 1 or Tray 2.
The CD mechanism can be shifted by using the DISC1/2 button.
TRAY-1 OPEN/CLOSE button: The Tray1 can be opened and closed.
TRAY-2 OPEN/CLOSE button: The Tray2 can be opened and closed.
LCD MODE
Display
*Afterthenumber 3 hasappearedinthedisplay,eachtimethe"UP/CUE"buttonispressed,thedisplaywillswitch
in the following order: 1 , 2 , and then 3 .
ELECTRONIC VOLUME TEST MODE
Operation VOL is set to -14 dB (LCD indication "5").
The VOL setting is changed as follows by using the "VOL UP" button or "VOL DOWN" button.
VOL UP button: VOL setting Min VOL setting -14 dB VOL setting Max
LCD indication "0" LCD indication "5" LCD indication "10"
VOL DOWN button: VOL setting Max VOL setting -14 dB VOL setting Min
LCD indication "10" LCD indication "5" LCD indication "0"
‘
‘
‘
‘
2
3
1
1 second1 second

GX-CH170X/CH170Z
TROUBLESHOOTING (CHANGER CONTROL SECTION)
When the changer mechanism fails to operate normally.
Operation failure may be caused by blocking of disc at the changer mechanism tray. Therefore, it is necessary to check at
first to see whether there is any disc blocking.
If no abnormal phenomena were found and the normal operation cannot be resumed, check as follows.
Does the CD mechanism move up and stop
when disc is selected?
Is "Er" displayed after normal stop? Check the optical pickup IN switch. (SW702)
Yes
No
Does LCD give an indication? Check as stated in item "CD MICROCOMPUTER OPERATION FAILURE".
No
Yes
Yes
No
Normal
•CDmicrocomputeroperationfailure.
Is +5V applied to the pin 7 of FW751?
Is +5V applied to the pin 25 (VDD) of IC901?
Yes
Yes
Is the oscillation circuit (periphery of XL701)
of IC901 normal? Yes
Is the tray opened when the OPEN/CLOSE
button is pressed?
Set the FUNCTION switch to CD.
Check as stated in item "THE DISC TRAY CANNOT BE OPENED AND CLOSED".
Check as stated in item "DISC CHANGE FAILURE".
No
Yes
Check for contact failure of Flexible wire. If OK, check the main PWB side power
line.
Check the pattern between FW751 and the pin 25 of IC901.
XL701 or IC901 is faulty.
Check the reset line.
Does LCD display appears when the pin 21
(RESET) of IC901 is instantaneously
connected to GND
Normal
Yes
Check voltage on the pins 41, 42, 43, and 44 of IC901. If OK, IC951 or LCD801 is
faulty.
Does the LCD indication change in the LCD
TEST mode?
Yes
No
No
No
No
No
– 11 –
Set the FUNCTION switch to REMOTE ON mode, and set the POWER button to ON.

GX-CH170X/CH170Z
No Check for breakage of connecting wire for loading motor M981C.
• The disc tray cannot be opened and closed.
Is +7.4V applied to the pin 6 of IC761?
Yes Check the +7.5V power line.
Does the LCD "?" indication rotate when the main unit
or remote control OPEN/CLOSE button is pressed? Check the main unit button or remote control.
Yes
Checkthatthe pin64ofIC901 isinLowstatebut thepin
1 is in High state when the OPEN/CLOSE button is
pressed. (Tray 1 unloading) (Tray 2 unloading: Pin 64
High, pin 1 Low)
No
No
No
Check that +6V is output to the pin 9 in Tray1 mode and
that +6V is output to the pin 7 in Tray2 mode.
Yes
Yes
No
No Check the pattern between IC761 and CNP753.
IC761 is defective.
Check IC901.
Is about +6V output between pins 4 and 5 of CNP753?
Yes
Is about +6V applied to the loading motor M981C?
Yes
Check the loading motor M981C and loading
mechanism.
M981C
Motor
operation
Tray1 Open H L 0 +6V Reverse
Tray2 Open L H +6V 0 Forward
Tray1 Close L H +6V 0 Forward
Tray2 Close H L 0 +6V Reverse
IC901 IC761
No IC901 is defective.
Check that the IC901 pin voltage is as follows:
Pin 1 Pin 64
Disc2 -> Disc1 L H
Disc1 -> Disc2 H L
Yes
No
Check that the IC761 pin voltage is as follows:
Pin 7 Pin 9
Disc1 -> Disc2 0 +6V
Disc2 -> Disc1 +6V 0
No Check for breakage of wire CNW753 to loading motor M981C.
Is voltage applied to the loading motor M781C?
IC761 is defective. Or check the pattern between pin 64 of IC901 and
pin 1 of IC761, the pattern between pin 1 of IC901 and pin 3 of IC761.
Yes
Yes
The motor M981C is defective.
•Disc change failure.
Is +7.4V applied to the pin 6 of IC761?
Does the LCD "?" indication rotate when the main unit
or remote control DISC CHANGE button is pressed? Check the main unit button or remote control.
Yes
No
Check the changer mechanism switches.
Disc move failure? Remains
persistently.
Operation
failure
Pin 1 Pin64 Pin 7 Pin 9
– 12 –

GX-CH170X/CH170Z
– 13 –
TROUBLESHOOTING (CD SECTION)
When the CD does not function
When the CD section does not operate When the objective lens of the optical pickup is dirty,this section may not operate.Clean
theobjective lens,and check the playback operation.Whenthis sectiondoes notoperateevenaftertheabove step is taken,check
the following items.
Remove the cabinet and follow the troubleshooting instructions.
"Trackskippingand/ornoTOC(TableOfContents)maybecausedbybuildupofdustotherforeignmatteronthelaserpickuplens.
Before attempting any adjustment make certain that the lens is clean. If not, clean it as mentioned below."
Turn the power off.
Gently clean the lens with a lens cleaning tissue and a small amount of isopropyl alcohol.
Do not touch the lens with the bare hand.
See if the pick-up is in the pick-up in SW4 position.
If the items mentioned above are OK, check the main
microcomputer IC901.
Yes
Yes
• The CD function will not work.
The CD operating keys don't work.
Check the CD, DPS microcomputer (IC701), power supply, 4.0
MHz and 16.93 MHz clock, and reset terminal.
Check the waveform of SCK, SO (DATA) and SI (COMM).
Yes
Yes
When the PLAY button is pressed without first loading a disc,
does the pickup go up and down?
Yes
Doesthe outputwaveformof IC801(16)(FD)match thatshownin
Fig. 13? Check the area around IC804-BI801/CNS801.
Yes
Check the IC801(50)(CLK) line, 4MHz.
Check the microcomputer data on pins (51)(CL), (52)(DAT) and
(53)CE.
Figure 13
• The CD operating keys work.
No
No
Does the pick-up move up and down twice? Focus search OK.
Focus search
is performed
two times
when play
operation is
done without
disc.
Check the Focus - HF system.
Yes
0.5s
0.50 V
IC801 16 FD
2
1
0.5s
0.50 V
IC801 15 TD

GX-CH170X/CH170Z
– 14 –
Check the laser diode driver.
• Playbackcanonly beperformedwhen adisc
is loaded.
Does the DRF signal change from "L" to "H"? No If the disc is not turning, the DRF
should not change to "H".
Is HF waveform normal (see the Fig.14-1, 2)?
Yes
Is the Focus servo active? (Can you hear it working?) No Check the area around IC801(16) - (21) (focus servo circuit).
Level is abnormal. Check the periphery
of IC801 pins 41 and
42.
No
Waveform is unstable. Check the spin
system.
Yes
Yes
Yes
Yes
Yes
Figure 14-2
Figure 14-1
Check the spin
system.
HF
0.1V/DIV
0.5µsec/DIV(DC)
(When playing
back the disc)
Waveform in case
of normal play-
back
3
2
1
4
0.5s
1.00 V
IC801 16 FD
0.5s
10.0 V
IC801 12 CLV+
0.5s
10.0 V
IC801 54 DRF
0.5s
2.00 V
IC801 7 TE
Check the tracking system.
• Check the tracking system.
Check waveform of IC801 pin 7 (TE).
Check the periphery of IC801
pin 8 to pin 15, and IC804 to
BI801/CNS801.
Tracking servo is inoperative.
The waveform shown in Fig. 14-3
appears, and no-disc state appears
soon. Yes
Yes
Yes Yes
Play is possible in
TEST mode. Although IL is possible,
play is impossible. Normal jump is impeded, and the
program top cannot be reached. Check the periphery of
IC801 pin 14.
Yes
Data cannot be read. Check the VCO-PLL system.
Yes
3
4
5ms
1.00 V
IC801 7 TE
5 ms
5.0 V
IC801 54 DRF
Figure 14-3

GX-CH170X/CH170Z
– 15 –
The turntable fails to rotate or rotates at high speed. Yes Check the periphery of IC801 pins 23 to 27, pin 39 and pin 40,
IC802 pin 12 and pin 13, IC804 to BI803/CNS803.
The turntable rotates a little. Yes The spin driver circuit is normal.
Play operation is performed without disc.
• Checking the spin system.
No
Yes
Check the IC801 pins 43 and 44, IC802 pins 3, 5, 7, 9 and 10.
Error
Yes Check PDO waveform (Fig. 15).
• Checking the VCO-PLL system
Play operation is performed when disc exits.
Yes
Although HF waveform is normal, TOC data cannot be read.
Figure 15
Check IC802 pins 37and 40.
Check the periphery of IC803 (OPAMP).
Abnomal
Usually, the number of pulses of flawless disc is 100 pulses/
sec or less.
No
Yes
Check IC802 pin 48 (EFLG).
• Although HF waveform is normal and the time
indication is normal, no sound is emitted.
As VCO freque-
ncy is locked at
4.32 M Hz,
voltage of PDO
rises and stabili-
zes.
Stop --> Play
2
3
0.5s
1.00 V
IC802 3 PDO
0.5s
1.00 V
IC801 16 FD

GX-CH170X/CH170Z
SW1 BAND [GX-CH170Z ONLY] FM—SW2—SW1
—MW
SW4 PICKUP IN ON—OFF
SW201 RECODE/PLAYBACK R—P
SW251 DUBBING SPEED/BEAT CANCEL NORMAL A—
NORMAL B—
HIGH C/A—B—C
SW253 BAND [GX-CH170X] FM—AM
SW253 TAPE SELECTOR/FM MODE NORMAL—CrO2/
[GX-CH170Z] FM STEREO—
FM MONO
SW601 TAPE 1 MAIN ON—OFF
SW602 TAPE 2 MAIN ON—OFF
SW603 TAPE1/2 SELECTOR ON—OFF
SW651 FUNCTION/REMOTO CONTROL CD—TUNER—
TAPE—OFF/
ON—OFF
SW701 POWER ON—OFF
– 16 –
NOTES ON SCHEMATIC DIAGRAM
1. Tuner
( ): AM mode
Marking except for ( ): FM mode
2. CD
( ): Play mode
Marking except for ( ): Stop state
3. Deck section
( ): Record mode
Marking except for ( ): Playback mode
Display / Control section:
( ): Active state
Marking except for ( ): CD Function mode at stop state
• Schematic diagram and Wiring Side of P.W.Board for this
model are subject to change for improvement without prior
notice.
• Parts marked with “ ” ( ) are important for
maintaining the safety of the set. Be sure to replace these
parts with specified ones for maintaining the safety and
performance of the set.
• Resistor:
To differentiate the units of resistors, the symbol as K and M
are used: the symbol K means 1000 ohm and the symbol M
means 1000 kohm and the resistor without any symbol is an
ohm resistor. The resistor designated "Fusible" is a fuse type
resistor
• Capacitor:
To indicate the unit of capacitor, a symbol P is used: this
symbolPmeansmicro-micro-faradandtheunitofthecapacitor
withoutsuchasymbolismicrofarad.Astoelectrolyticcapacitor,
the expression “capacitance/withstand voltage” is used.
(CH), (TH), (RH), (UJ): Temperature compensation
(ML): Mylar type
(P.P.): Polypropylene type
•Theindicatedvoltageineachsection is the one measured by
Digital Multimeter between such a section and the chassis
with no signal given.
REF. NO DESCRIPTION POSITION
SW702 CD-STOP ON—OFF
SW703 CD-PLAY ON—OFF
SW704 CD-PAUSE ON—OFF
SW705 CD-CUE ON—OFF
SW706 CD-REVIEW ON—OFF
SW707 CD-DISC 1-2 ON—OFF
SW708 CD-RANDOM ON—OFF
SW709 VOLUME UP ON—OFF
SW710 VOLUME DOWN ON—OFF
SW711 CD-PROGRAM ON—OFF
SW712 CD-CLEAR ON—OFF
SW713 CD-TRAY1 OPEN/CLOSE ON—OFF
SW714 CD-TRAY2 OPEN/CLOSE ON—OFF
SW981 TRAY/MECHANISM UP ON—OFF
SW982 TRAY1 1a—1b
SW983 TRAY2 2a—2b
REF. NO DESCRIPTION POSITION
Figure 16 TYPES OF TRANSISTOR AND LED
ECB
(S)(G)(D)
(1) (2) (3)
FRONT
VIEW
BCE
FRONT
VIEW
2SC2001 K
2SB561 C
2SB562 C
2SD468 C
KRA102 M
KRC102 M
KTA1266 GR
KTC3199 GR
2SD2394 F
FRONT
VIEW
FRONT
VIEW
2
3
GREEN 1
RED
3N8PGN33
3N4PDN32
3N4GDN32

GX-CH170X/CH170Z
Figure 17 BLOCK DIAGRAM (1/3)
– 17 –
1
2
3
4
5
6
7
8 9
10
11
12
1
2
3
4
5
6
37
33
32
11
4
2
43
22
6
4544
44
43
40
9
10
12
13
14
15
16
17
18 19
20
1
53
38 39 51 62 64 6158
63
32
64 62
1
2
3
4
30 49 54
15 16 27 28 29
3
10 19 23 25
22
5
6
7
8
13
28
11
12
1
2
17
18
26
27
8
46
31
+5V
FOCUS COIL
TRACKING COIL
PICKUP UNIT
MOTOR
SPIN
SQOUT
PUIN RES COIN CQCK
RWC
SL+
SL– DRF WRQ
CNS852
GND(A) R-CH L-CH +7.4V GND(D)
CNS851
GND(P)
TO MAIN SECTION
+7.4V
(CD)
LCHO
XVDD
VVDD
VDD
XIN
XOUT
~
EFMO EFMIN CLV+ CLV– V/P HFL TES TOFF TGL JP+ JP–
~
IC802
LC78622E
SERVO/SIGNAL
CONTROL
SLI
SLC
CV+
JP–
Q805
+5V
FIN1 E F
LDO
VCC1
FIN2
~
FD
SPO
SLEO
SLD
/THLD
DEF
SL+
SL–
DRF
TO
CL, DAT, SELIAL CONTROL
+7.4V
Q804+5V
M
M701
SW702
PICKUP IN
DRIVER
LASER
M
M702
SLIDE
MOTOR
IC801
LA9240M
SERVO AMP.
CD-GND
DEF1,4MCLK,
RES,CQCK,
COIN,SQOUT,
RWC,WRQ
16.93MHz
XL801
FOCUS/TRACKING
/SPIN/SLIDE
DRIVER
IC804
BA5920FP
CD 5V
TO
MICROCOMPUTER

GX-CH170X/CH170Z
Figure 18 BLOCK DIAGRAM (2/3)
– 18 –
3
12
3
21 98
7
6
5
4
3
2
1
13121110 13121110
98
7
6
5
4
123456789
10 11 12 13 14
17
18
19
20 21
22 23
24
25 26
27
28
29
30
31
32
41
4243
44
53
54
55
6
5
57
58 59
60
1
6
33
3435
36
37
38
39
40
62
64 63
987654321
1
10
9
8
7
6
5
4
3
2
11
12
7
98 654321
1
7
98 65432
23456789
10 11
1
10
11
10
11
12 13
LED704LED703LED701
POWER TRY-2TRY-1
KEY1
KEY2
TRY1 LED
TRY2 LED
PWR-IN
VREF
GND
FW702
POWER-CD-VOL
OPERATION KEY
SW701 ~ SW714
REMOTE SENSOR
RX701
FW701
LED CONTROL
Q711 ~ Q715
VSS
Q704Q702
RESET
BEAT
µ-COM5V
COM3
COM2
COM1
COM0
SEG7 SEG8
SEG SEG SEG SEG SEG SEG SEG
VLC2
VLC1
VLC3
KEY1
KEY2
UP-SW
TRAY SW
MODEL
CD/SYC-IN
AC/DC
REMOCON
VREF
AVSS
XC-IN
XC-O
VDD
VSS
X-OUT
X-IN
PU-IN
WRQ
SQ-OUT
DRF
RESET
MTR2
PWR-IN
DATA(VOL)
STB(VOL)
MUTE
SYC-OUT
RES
CQCK
C0IN
RWC
SL+
SL–
CK(VOL)
PWR-0N
TR1 LED TR2 LED
MTR1
Q705
Q701 Q703
AC-ON
PLUS
POWER
PUIN WRQ COIN CQCK RES CD5V CD-GND DRF SL– SL+ RWC SQOUT
FROM
CD-SERVO SECTION
+
–
M
SW981
TRAY/
MECHANISM UP
TRAY2
SW983
M981
LOADING
MOTOR
SW982
TRAY1
REMOCON
CH7.4V
P-GND
VOL(STB)
VOL(CK)
VOL(DATA)
GND
MUTE
POW-ON
CD/SYC-IN
TWEET CANCEL
FW751
TO MAIN SECTION
X701
4MHz
IC901
IX0146AW
SYSTEM
MICROCOMPUTER
BA6218
IC761
CHANGER
MOTOR CONTROL
µ-COM5V
AC-ON
µ-COM5V
LCD801 CD LCD
CANCEL
PWR-ON
AC-ON HI
SY OUT

GX-CH170X/CH170Z
Figure 19 BLOCK DIAGRAM (3/3)
– 19 –
15
20
1
7
48
6
9
5
32
4
12
8
19 18
9
10
21
7
14
15
13
1116
17
32
22
23
15
12
13
9
19
1
24
7
18
19
11
8
5
12
10
6
2
19
2
18
3
20
7
24
2
5
4 3 1
6
11 12 13
123456789
10 11 12
21
4
23
2
13
6
13
CF2
10.7MHz CF3
AM IF
T1
FM IF
P. B REC
REC/PB
REC/PB
HEAD
L-CH R-CH
T3
P. B
FM DET
T2
L2
FM OSC
FM +B
L1
FM RF
ERASE
HEAD
REC
RF
REG.
MPX
OSC AGC
DET.
AM-IF
LEVEL-DET.
FM-IF DET. AMP.
POST
MUTE
DRIV. TU DECODER
DET. PHASE VCO FF FF
PILOT DET. ST.
DRIV.
FF
ST. SWIT.
TRIG.
VCC
ROD ANTENNA
L R
R L R L
SW201
P. B
L-CH R-CH
REC
T1/T2
T1/T2
TUNER
+B
R L
+B1
P. B
455kHz AM
+B2
AC INPUT
T651
POWER
TRANSFORMER
VR1 VCO MONO
T2 PB HEAD
T1
L(T2) R(T2) L(T1) R(T1)
WOOFER
WOOFER
Q623
CNP601
SP602
D651 ~ D654
RECTIFIER
MUTING
VR391 M601
TAPE MOTOR
REC
R-CH AUDIO L-CH
CD+7.3V POWER GND
GND
CD
BATTERY
DC 12V
AC ON
SW201-B
REC/PB
SW201-A
REC/PB
+
+
–
–
J601 HEADPHONES
TWEETER SP603
L-CH
SP601
SP604 TWEETER
R-CH
SPEAKERS
Q651
Q657 Q653
µ-COM+5V Q654
Q652
POWER ON
SWITCHING
SWITCHING
POWER-ON
+12V Q658
Q659
POWER
VOLTAGE
REGULATOR +B1
REGULATOR
VOLTAGE
7.4V FUNCTION
POWER/
REGULATOR VOLTAGE
SWITCHING
CD/SYNC-IN
SYNC-IN
Q656 Q655
Q662
STAND-BY
LA4597
IC601
MUTING
Q521 Q522
MUTE
DRIVER
TUNER +B
AUDIO +B
SW651-B
CANCEL
SW251-B
SW651-B
FUNCTION
FM +B
TO µ-COM SECTION
P-GND
CH7.4V
GND
MUTE
POW-ON
AC-ON
CD / SYC-IN
TWEET CANCEL
13
SYC-OUT
VOL(CK)
VOL(STB)
VOL(DATA)
Q202 Q201
FUNCTION SW651-C, D
RADIO
Q660
DUBBING
SWITCHING
Q393 Q394
SWITCHING
M
TAPE SPEED
Q392
Q391
Q252
BIAS OSC. Q351 L351
C, D, E, F
SELECTOR
SW607
CNP851
TO CD SERVO
SECTION
F1
B. P. F
FM FRONT END
LA1186N
IC1
IC2
LA1805
FM/AM IF MPX.
TAPE
ELECTRONIC
VOLUME
IC500
TC9211P
POWER AMP.
[ "D" size ( UM/SUM-1,
R20 or HP-2 ) battery x 8]
SW601 T1 MAIN SW602 T2 MAIN
DUBBING
SW251
SPEED/
BEAT
CANCEL
TWEET
IC201
AN7345K
PLAYBACK AND
RECORD/PLAYBACK
AMP.
µ-COM5V
SO651
FOR Z
FOR X
X : AC 220-240V
50Hz
Z : AC 110-127
/220-240V
50/60Hz
SW651-A FUNCTION
POWER-ON
12V
TAPE +B
X ONLY
TAPE +B
MOTOR-CONT
SELECTOR TAPE SW253-B Z ONLY
Q352 Q353 Q362 Q363 X ONLY
Z ONLY
F661
T500mA
L 250V
TUNER +B
TUNER +B
SW253-A
Z ONLY
SW253
X : BAND
Z : TAPE
SELECTOR
GND
AM OSC. L5 L7
SW2 OSC.
L4
SW1 OSC.MW OSC.
BAND SW1-E
FOR Z
L4
FOR X
CNP751
F662
T500mA
L 250V
8KHz
VR904
A, B
1KHz
VR903
A, B
125Hz
VR902
A, B
Q901
Q902
EQUALIZER
GRAPHIC
X-BASS
A, B
VR901
AM BAR ANT.
L3
FOR X
SW1-C
BAND
BAR ANT.
MW/SW1
L3
FOR X
RF AMP.
MIX OSC
VCC
F1
B.P.F
ROD ANTENNA
L6
SW2 ANT.
BAND SW1-A
FOR Z
FOR Z
X : GX-CH170X Z : GX-CH170Z
F651
T2.5A
L 250V
F663
T1.25A
L 250V

GX-CH170X/CH170Z
Figure 20 WIRING OF P.W.BOARD (1/8)
The numbers 1 to 12 are waveform numbers shown in page 35.
– 20 –
A
B
C
D
E
F
G
H
1234 5 6
16
R829
XL801
R873
R805
R834
CNS803
CNP851
C887
R875
C869
R876
C870 R874 C868
C867
L801
R877
C889
ZD801
C846
X:JUMPER
Z:D803
R878
R824
R825 R831
C820
C819
R823
R822
C818
C844 C817
R830 R840
R839
18
BI801
IC804
R810
C848
R842
C849 R828
C813
R812
R813
C811
Q805
C815
R820
R821
R819
C816 R817
C812
R816
C814
R815
R814
C809
R806
C807
R804
R802
R803
C804
C805
C803
C806
R807
C808
R809
R811
R808
C810
15
BI802
C801
R801
C802
C837
C839
C838
C840
C850
R871
C845
C835
C834
R836
R838
C851
R849
C821
D802
R858
C841
C847
R860
C833
C842
R857
R856
R837
R835
C831
R832
C832
R833
C830
C873
C843
Q804
C822
R827
R826
CNP852
17814
15212228
R880
B
C
E
B
C
E
164
5
10 15 16
17
20
25
30
32
33
35
40
45
50
49 48
55
60
IC802
164
5
10 15 16
1720
25
30
32
33
35
40
45
50
49 48
55
60
IC801
+
-
+
-
PICKUP IN
654321
SLIDE MOTOR
SPIN MOTOR
M702
CNP803
SW702
M701
BR
COLOR TABLE
RD(R)
OR
YL
GR
BL
VL
GY
WH(W)
BK
PK
BROWN
RED
ORANGE
YELLOW
GREEN
BLUE
VIOLET
GRAY
WHITE
BLACK
PINK
CNS803 RD
WH
GY
WH
GY
WH
1
2
3
4
5
6
RD
WH
GY
WH
GY
23456781
CNS801
CNS802
123456
BL GR YL OR RD BR GY BK GY BK GY BK GY BK GY BK GY RD
123456789101112
CNP851
CNS851 CNS852
P25 11 - C [X]
P27 11 - C [Z]
TO MAINN PWB
CNP852
P30 5 - B
TO DISP PWB
RD WH GY WH GY WH GY WH
12345
PICKUP UNIT
CD MOTOR PWB-E
CD SERVO PWB-D
1 8
6
7 12 10
5
4
32
9
11