Sony HCD-GNX780 User manual

HCD-GNX780/GNX880
Mexican Model
SERVICE MANUAL
MiNi Hi-Fi COMPONENT SYSTEM
SPECIFICATIONS
Ver. 1.1 2006.09
– Continued on next page –
•HCD-GNX780/GNX880 is the Amplifier,
Disc player, tape deck and tuner
section in MHC-GNX780/GNX880.
Model Name Using Similar Mechanism HCD-GN880
CD CD Mechanism Type CDM74KF-F1BD84
Section Base Unit Name BU-F1BD84
Optical Pick-up Name KSM-215DCP/C2NP
TAPE Model Name Using Similar Mechanism HCD-GNX80
Section Tape Transport Mechanism Type CWN42FF601
Amplifier section
HCD-GNX880
The following are measured at AC 127 V, 60 Hz
Front/Surround speaker
DIN power output (rated) 180 + 180 watts
(6 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
225 + 225 watts
(6 ohms at 1 kHz, 10% THD)
Subwoofer
Continuous RMS power output (reference)
200 watts
(8 ohms at 100 Hz, 10% THD)
HCD-GNX780
The following are measured at AC 127 V, 60 Hz
Front speaker
DIN power output (rated) 210 + 210 watts
(4 ohms at 1 kHz, DIN)
Continuous RMS power output (reference)
285 + 285 watts
(4 ohms at 1 kHz, 10% THD)
Inputs
VIDEO/MD (AUDIO) IN (phono jacks):
voltage 250/450 mV,
impedance 47 kiloohms
TV (AUDIO) IN (phono jack): voltage 250 mV,
impedance 47 kiloohms
MIC (phone jack): sensitivity 1 mV,
impedance 10 kiloohms
Outputs
VIDEO OUT (phono jack): max. output level
1 Vp-p, unbalanced, Sync negative,
load impedance
75 ohms
PHONES (stereo mini jack): accepts headphones of 8 ohms or more
FRONT SPEAKER/SURROUND SPEAKER/
SUBWOOFER OUT: Use only the supplied speaker
Photo: HCD-GNX880
Sony Corporation
Home Audio Division
Published by SonyTechno Create Corporation
9-887-130-02
2006I02-1
© 2006.09

2
HCD-GNX780/GNX880
Notes on chip component replacement
•Never reuse a disconnected chip component.
•Notice that the minus side of a tantalum capacitor may be
damaged by heat.
Flexible Circuit Board Repairing
•Keep the temperature of soldering iron around 270˚C
during repairing.
•Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
•Be careful not to apply force on the conductor when soldering
or unsoldering.
CAUTION
Use of controls or adjustments or performance of procedures
other than those specified herein may result in hazardous
radiation exposure.
This appliance is classified as
a CLASS 1 LASER product.
This label is located on the rear
exterior.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED LINE WITH
MARK 0ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY.
Unleaded solder
Boards requiring use of unleaded solder are printed with the lead
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size.)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
•Unleaded solder melts at a temperature about 40°C higher than
ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350°C.
Caution: The printed pattern (copper foil) may peel away if
the heated tip is applied for too long, so be careful!
•Strong viscosity
Unleaded solder is more viscous (sticky, less prone to flow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
•Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
Disc player section
System Compact disc and digital
audio system
Laser Semiconductor laser
(λ=780 nm)
Emission duration: continuous
Laser Output Max. 44.6 µW*
* This output is the value measured at
a distance of 200 mm from the
objective lens surface on the Optical
Pick-up Block with 7 mm aperture.
Frequency response 2 Hz – 20 kHz (±0.5 dB)
Wave length 780 – 790 nm
Signal-to-noise ratio More than 90 dB
Dynamic range More than 90 dB
OPTICAL CD DIGITAL OUT
(Square optical connector jack, rear panel)
Wave length 660 nm
Output Level –18 dBm
Tape deck section
Recording system 4-track 2-channel stereo
Frequency response 50 – 13,000 Hz (±3 dB),
using Sony TYPE I tape
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 – 108.0 MHz
Antenna FM lead antenna
Antenna terminals 75 ohm unbalanced
Intermediate frequency 10.7 MHz
AM tuner section
Tuning range 530 – 1,710 kHz
(with the interval set at 10 kHz)
531 – 1,710 kHz
(with the interval set at 9 kHz)
Antenna AM loop antenna
Antenna terminals External antenna terminal
Intermediate frequency 450 kHz
General
Power requirements 127 V AC, 60Hz
Power consumption
MHC-GNX880 350 watts
MHC-GNX780 250 watts
Dimensions (w/h/d) (Approx.) 281 ×362 ×404.5 mm
Mass (Approx.)
HCD-GNX880 13.7 kg
HCD-GNX780 12.0 kg
Design and specifications are subject to change without notice.

3
HCD-GNX780/GNX880
TABLE OF CONTENTS
1. SERVICING NOTES ................................................ 4
2. GENERAL
Locating the Controls ...................................................... 5
3. DISASSEMBLY
3-1. Disassembly Flow ........................................................... 7
3-2. Side Panel, Top Case ....................................................... 8
3-3. Loading Panel .................................................................. 8
3-4. Front Panel Assy .............................................................. 9
3-5. Tuner Pack ....................................................................... 9
3-6. Tape Mechanism Deck, MIC Board ................................ 10
3-7. CD-SW Board, PANEL Board ........................................ 10
3-8. FUNCTION Board, JOG Board ...................................... 11
3-9. CD Mechanism Deck ...................................................... 11
3-10. Back Panel ....................................................................... 12
3-11. PRIMARY Board, EFFECTOR Board............................ 12
3-12. Power Amp PC Board Assy, MAIN Board ..................... 13
3-13. SURROUND Board, PA Board ....................................... 13
3-14. Power Transformer (T1200) ............................................ 14
3-15. CDG Board, DRIVER Board, SW Board ....................... 14
3-16. BD84 Board ..................................................................... 15
3-17. SENSOR Board ............................................................... 15
3-18. MOTOR (TB) Board ....................................................... 16
3-19. MOTOR (LD) Board ....................................................... 16
4. TEST MODE .............................................................. 17
5. MECHANICAL ADJUSTMENTS ....................... 21
6. ELECTRICAL ADJUSTMENTS
Deck section .................................................................... 21
CDG Section.................................................................... 22
7. DIAGRAMS
7-1. Block Diagram – CDG Section – ................................... 27
7-2. Block Diagram – Tape/Tuner Section – ......................... 28
7-3. Block Diagram – Main Section – ................................... 29
7-4. Block Diagram – AMP Section – ................................... 30
7-5. Block Diagram – Display/Power Section – .................... 31
7-6. Printed Wiring Board – BD84 Board – .......................... 32
7-7. Schematic Diagram – BD84 Board – ............................. 33
7-8. Printed Wiring Boards – CD Mechanism Sectiom – ...... 34
7-9. Schematic Diagram – CD Mechanism Section – ........... 35
7-10. Printed Wiring Board – MAIN Board – ......................... 36
7-11. Schematic Diagram – MAIN Board (1/3) – ................... 37
7-12. Schematic Diagram – MAIN Board (2/3) – ................... 38
7-13. Schematic Diagram – MAIN Board (3/3) – ................... 39
7-14. Printed Wiring Board – PANEL Board – ....................... 40
7-15. Schematic Diagram – PANEL Board – ........................... 41
7-16. Printed Wiring Boards
– CD-SW, JOG, MIC and FUNCTION Boards – ........... 42
7-17. Schematic Diagram
– CD-SW, JOG, MIC and FUNCTION Boards – ........... 43
7-18. Printed Wiring Board – PA Board – ............................... 44
7-19. Schematic Diagram – PA Board – .................................. 45
7-20. Printed Wiring Board – SURROUND Board – .............. 46
7-21. Schematic Diagram – SURROUND Board – ................. 47
7-22. Printed Wiring Board – EFFECTOR Board – ................ 48
7-23. Schematic Diagram – EFFECTOR Board – ................... 49
7-24. Printed Wiring Board – CDG Board – ........................... 50
7-25. Schematic Diagram – CDG Board – .............................. 51
7-26. Printed Wiring Boards – Power Section – ...................... 52
7-27. Schematic Diagram – Power Section – .......................... 53
7-28. IC Pin Function Description ............................................ 58
8. EXPLODED VIEWS
8-1. Case (Top), Back Panel Section ...................................... 64
8-2. Front Panel Section-1 ...................................................... 65
8-3. Front Panel Section-2 ...................................................... 66
8-4. Chassis Section ................................................................ 67
8-5. CD Mechanism Deck Section-1
(CDM74KF-F1BD84) ..................................................... 68
8-6. CD Mechanism Deck Section-2
(CDM74KF-F1BD84) ..................................................... 69
9. ELECTRICAL PARTS LIST ................................ 70

4
HCD-GNX780/GNX880
SECTION 1
SERVICING NOTES
NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK
OR BASE UNIT
The laser diode in the optical pick-up block may suffer electrostatic
break-down because of the potential difference generated by the
charged electrostatic load, etc. on clothing and the human body.
During repair, pay attention to electrostatic break-down and also
use the procedure in the printed matter which is included in the
repair parts.
The flexible board is easily damaged and should be handled with
care.
NOTES ON LASER DIODE EMISSION CHECK
The laser beam on this model is concentrated so as to be focused on
the disc reflective surface by the objective lens in the optical pick-
up block. Therefore, when checking the laser diode emission, observe
from more than 30 cm away from the objective lens.
LASER DIODE AND FOCUS SEARCH OPERATION CHECK
Carry out the “S curve check” in “CD section adjustment” and check
that the S curve waveform is output several times.

5
HCD-GNX780/GNX880
SECTION 2
GENERAL This section is extracted
from instruction manual.
LOCATING THE CONTROLS
Main unit
ALBUM +/– ql
AMP MENU ed
CD r;
CD SYNC qf
Deck A ef
Deck B ws
DELAY ea
DIRECTION wd
DISC 1 ~ 3 1
Disc tray qs
DISPLAY 6
Display q;
ECHO LEVEL wh
ENTER wg
EQ BAND wf
EX-CHANGE/DISC SKIP 2
FLANGER 7
GROOVE w;
ILLUMINATION 5
IR Receptor ra
KARAOKE wd
MASTER VOLUME wk
MIC 1/2 (jack) wl
MIC 1/2 LEVEL wj
MP3 BOOSTER qa
OPEN/CLOSE 3
OPERATION DIAL 4
PHONES (jack) es
Power illuminator 9
REC PAUSE/START qd
SOUND FLASH e;
SURROUND
1) 8
SURR SPEAKER MODE2) 8
TAPE A/B ek
Tape lid ws ef
TUNER/BAND el
TUNING +/– qk
TV ej
VIDEO/MD eh
?/1 (power) rs
ZOPEN/CLOSE 3
N (play) qg
>/. (forward/go backward) qk
M/m (fast forward/rewind) ql
X(pause) qh
x(stop) qj
AZ (Eject A) eg
B Z(Eject B) wa
1)For MHC-GNX780
2)For MHC-GNX880
ALPHABETICAL ORDER
A – D
E – L
M – R
S – Z
SYMBOLS
Top Panel
Front Panel
2
4
13
56
78 9q;qaqs
qd
qf
qg
qh
qj
qk
ql
w;
wa
ws
wg
wf
wd
whwjwkwle;eaes
ed
ef
eg
eh
ej
ek
el
r;
ra
rs

6
HCD-GNX780/GNX880
This section is extracted
from instruction manual.
Remote control
ALBUM + qf
ALBUM – qh
CD wf
CLEAR qk
CLOCK/TIMER SELECT 2
CLOCK/TIMER SET 4
DISC SKIP qd
DISPLAY wh
ENTER qs
EQ qj
FM MODE 6
FUNCTION 8
PLAY MODE 5
REPEAT 6
SLEEP 1
TAPE wd
TUNER/BAND 7
TUNER MEMORY wg
TUNING MODE 5
VOLUME +/– qg
The + button has a tactile dot.*
?/1 (power) 3
x(stop) qa
X(pause) ql
N (play) w;
–.(go backward) ws
>+ (go forward) wa
m(rewind) q;
M(fast forward) 9
*Usethe tactile dot as a reference
when operating the system.
ALPHABETICAL ORDER
A – E
F – Z
SYMBOLS
7
5
q;
qg
qh
qj
qk
w;
ws
wd
wg
wh
qf
qd
qs
qa
9
8
6
4
3
12
ql
wa
wf
Use buttons on the remote for the operation.
1 Press ?/1 to turn on the system.
2 Press CLOCK/TIMER SET.
“CLOCK” appears in the display. Then, the
hour indication flashes in the display.
3 Press –.or >+repeatedly to set
the hour.
4 Press ENTER.
The minute indication flashes in the
display.
5 Press –.or >+ repeatedly to set
the minute.
6 Press ENTER.
The clock starts functioning.
To adj ust the c lock
1 Press CLOCK/TIMER SET.
“SET” appears in the display, then “PLAY
SET?” flashes in the display.
2 Press –.or >+ repeatedly to select
“CLOCK SET?”, then press ENTER.
The hour indication flashes in the display.
3 Do the same procedures as step 3 to 6
above.
Not es
The clock settings are canceled when you disconnect
the power cord or if a power failure occurs.
You cannot set the clock in Power Saving Mode
.
Setting the clock

7
HCD-GNX780/GNX880
SECTION 3
DISASSEMBLY
• This set can be disassembled in the order shown below.
3-1. DISASSEMBLY FLOW
3-2.SIDE PANEL, TOP CASE
(Page 8)
3-3.LOADING PANEL
(Page 8)
3-4.FRONT PANEL ASSY
(Page 9)
3-5.TUNER PACK
(Page 9)
3-14.POWER TRANSFORMER
(T1200)
(Page 14)
3-12.POWER AMP PC BOARD ASSY,
MAIN BOARD
(Page 13)
3-9.CD MECHANISM DECK
(Page 11)
3-7.CD-SW BOARD,
PANEL BOARD
(Page 10)
3-6.TAPE MECHANISM DECK,
MIC BOARD
(Page 10)
3-15.CDG BOARD,
DRIVER BOARD,
SW BOARD
(Page 14)
3-11.PRIMARY BOARD
EFFECTOR BOARD
(Page 12)
3-18.MOTOR (TB) BOARD
(Page 16)
3-19.MOTOR (LD) BOARD
(Page 16)
3-17.SENSOR BOARD
(Page 15)
3-13.SURROUND BOARD,
PA BOARD
(Page 13)
3-8.FUNCTION BOARD,
JOG BOARD
(Page 11)
3-10.BACK PANEL
(Page 12)
3-16.BD84 BOARD
(Page 15)
SET

8
HCD-GNX780/GNX880
Note: Follow the disassembly procedure in the numerical order given.
3-2. SIDE PANEL, TOP CASE
3-3. LOADING PANEL
1 screw (case 3 TP2)
(3
× 8)
2 two screws
(case 3 TP2)
(3
× 12)
3 two screws
(+BVTP 3
× 10)
4
5
PANEL (SIDE-R)
6 screw
(case 3 TP2)
(3 × 8)
7 two screws
(case 3 TP2)
(3
× 12)
8 two screws
(+BVTP 3
× 10)
9
0
PANEL (SIDE-L)
qa two screws
(+BVTP 3
× 12)
qs
qd
CASE (TOP)
CD mechanism deck (CDM74KF-F1BD84)
1 Turn the pulley to the arrow direction.
Front side
Pulley
2 Pull out disc tray
3
4
loading panel

9
HCD-GNX780/GNX880
3-4. FRONT PANEL ASSY
3-5. TUNER PACK
1 three screws
(+BVTP 3
× 10)
2 three screws
(+BVTP 3
× 10)
3 screw
(+BVTP 3
× 10)
4 screw
(+BVTP 3
× 10)
5 front panel assy
6 connector
(CN100)
7 wire (flat type)
(CN508)
8 wire (flat type)
(CN509)
9 connector
(CN503)
q; connector
(CN1102)
qa connector
(CN507)
1 two screws
(+BVTP 3 × 6)
2 wire (flat type)
(CN1)
3 tuner pack

10
HCD-GNX780/GNX880
3-6. TAPE MECHANISM DECK, MIC BOARD
3-7. CD-SW BOARD, PANEL BOARD
1 three screws
(+BVTP2.6 (3CR))
2 two screws
(+BVTP2.6 (3CR)
)
3 tape mechanism deck
4 three screws
(+BVTP2.6 (3CR))
5 bracket (MIC)
7 MIC board
6 knob (MIC)
5 three screws
(+BVTP2.6 (3CR))
1 two screws
(+BVTP2.6 (3CR))
6 wire (flat type)
(CN900)
7 wire (flat type)
(CN902)
4 three screws
(+BVTP2.6 (3CR))
3 CD-SW board
8 PANEL boar
d
CD-SW board
CD-SW board
bracket portion
button (DISC)
button (DISC)
button (DISC)
(side view)
bracket portion
AA
B
B
2 Pull up the bracket portion of button (DISC) in the arrow A direction and
pull out CD-SW board in the arrow
B direction.

11
HCD-GNX780/GNX880
3-8. FUNCTION BOARD, JOG BOARD
3-9. CD MECHANISM DECK
3 FUNCTION board
2 nine screws
(+BVTP2.6 (3CR))
5 two screws
(+BVTP2.6 (3CR))
6 two screws
(+BVTP2.6 (3CR))
1 knob vol
4 knob jog assy
7 JOG board
MAIN board
2 CD mechanism deck
4 wire (flat type)
(CN701)
6 wire (flat type)
(CN504)
5 connector
(CN560)
3 wire (flat type)
(CN505)
1 two screws (+BVTP 3 × 8)

12
HCD-GNX780/GNX880
3-10. BACK PANEL
3-11. PRIMARY BOARD, EFFECTOR BOARD
1 connector
(CN1200)
2 connector
(CN1204)
3 wire (flat type)
(CN1501)
6 two screws (GNX880)
screw (GNX780)
(+BVTP 3 × 10)
4 five screws
(+BVTP 3 × 10)
5 two screws
(+BVTP 3 × 12)
7 two screws
(+BVTP 3 × 12)
9 connector
(CN580)
8 back panel
1 connector
(CN101)
2 connector
(CN201)
3 screw
(+BVTP 3
× 8)
5 two screws
(+BVTP 3
× 10)
4 PRIMARY board
6 EFFECTOR board

13
HCD-GNX780/GNX880
3-13. SURROUND BOARD, PA BOARD
3-12. POWER AMP PC BOARD ASSY, MAIN BOARD
1 connector
(CN1213)
2 connector
(CN1212)
8 connector
(CN105)
3 screw
(+BV3 (3-CR))
4 two screws
(+BV3 (3-CR))
5 screw
(+BV3 (3-CR))
6 screw
(+BVTP 3
× 10)
7 power AMP PC board assy
9 two screws
(+BVTP 3
× 10)
q; screw
(+BVTP 3
× 10)
qa MAIN board
(GNX880)
4 connector
(CN607)
1 two screws
(+BVTP 3
× 10)
2 two screws
(transistor)
3 SURROUND board
5 two screws
(+BVTP 3
× 10)
6 holder
7 three screws
(+BVTP 3
× 10)
8 two screws
(transistor)
9 two screws
(+BVTP 3
× 10)
qa screw
(+BVTP 3
× 10)
0 heat sink
qs bracket
(GNX880)
qd PA board
(GNX880)

14
HCD-GNX780/GNX880
3-14. POWER TRANSFORMER (T1200)
3-15. CDG BOARD, DRIVER BOARD, SW BOARD
1 connector
(CN1213)
2 connector
(CN1212)
3 two screws
4 two screws
5 power transfomer (T1200
)
TRANS board
7 connector (CN703)
4 cover (CDM)
8 DRIVER board
2 CDG board
0 SW board
6 wire (flat type) (CN702)
5 two screws
(+BTTP (M2.6))
3 three screws
(+BVTP 3
× 10
)
1 two screws
(+BVTP 3
× 10)
9 screw
(+BTTP (M2.6))

15
HCD-GNX780/GNX880
3-16. BD84 BOARD
3-17. SENSOR BOARD
5 two coil springs
(insulator)
9 two coil springs
(insulator)
6 two insulators
0 two insulators
qs s crew (+BVTP 2.6 (3CR))
7 t wo screws
(+BTTP (M2.6))
3 screw
(+BTTP (M2.6))
2 h older (213) ASSY
8 t wo stoppers (BU)
qd Remove the four solderings of motor.
qf CN101 (flat type)
qg BD84 board
qh optical pick-up
(KSM-215DCP/C2NP)
1 floating screw
(+PTPWH M2.6)
4 floating screw
(+PTPWH M2.6)
qa
2 t ray
3 b elt (table)
5 p ulley (table)
8 s crew
(+BTTP (M2.6))
0 SENSOR board
7 g ear (geneva)
9 connector
( CN731)
1 floating screw
(+PTPWH M2.6)
6 floating screw
(+PTPWH M2.6)
4 floating screw
(+PTPWH M2.6)

16
HCD-GNX780/GNX880
3-18. MOTOR (TB) BOARD
6 Remove the two solderings of motor.
8 MOTOR (TB) board
7 t able motor assy (M741)
5 two screws
(+BTTP (M2.6))
4
3
wire (flat type) 5 core (CN742)
1 stopper
2 stopper
3-19. MOTOR (LD) BOARD
4 Remove the two solderings of motor.
3 MOTOR (LD) board
1 b elt (loading)
5 l oading motor assy (M751)
2 two screws
(+BTTP (M2.6))

17
HCD-GNX780/GNX880
[MC TEST MODE]
•This mode is used to check operations of the respective sections
of Amplifier, Tuner, and Tape.
Procedure:
* To enter MC Test Mode
1. Press xbutton, [ENTER] button and [DISC 3] button
simultaneously.
2. The CD ring indicators TAPE A and B indicators flash on the
fluorescent indicator tube. The function is changed to TV.
* Check of Amplifier
1. Press [EQ BAND] button repeatedly until a message “GEQ
MAX” appears on the fluorescent indicator tube. GEQ
increases to its maximum.
2. Press [EQ BAND] button repeatedly until a message “GEQ
MIN” appears on the fluorescent indicator tube. GEQ decreases
to its minimum.
3. Press [EQ BAND] button repeatedly until a message “GEQ
FLAT” appears on the fluorescent indicator tube. GEQ is set
to flat.
4. When the [VOLUME] knob is turned clockwise even slightly,
the sound volume increases to its maximum and a message
“VOLUME MAX” appears on the fluorescent indicator tube.
5. When the [VOLUME] knob is turned counter-clockwise even
slightly, the sound volume decreases to its minimum and a
message “VOLUME MIN” appears on the fluorescent
indicator tube.
* Tape function
1. When a tape is inserted in Deck B and recording is started, the
function is changed to TV automatically. When [CD SYNC]
button is pressed during recording in function, ALC (Automatic
Logic Control) is turned on.
2. During recording, press
m
will stop the recording and
the function is changed to TAPE B and rewind the tape in
Deck B until the recording start position and playback of the
tape in Deck B is started. If the [REC PAUSE/ START] button
is pressed for a pause and pressed again to resume recording
during recording time, when the tape is rewind, the tape will
be rewind until the position where the pause is applied.
* To release MC Test mode.
1. To release this mode, press ?/1 button.
2. The cold reset is enforced at the same time.
[COLD RESET]
•The cold reset clears all data including preset data stored in
the RAM to initial conditions. Execute this mode when
returning the set to the customer.
Procedure:
1. Press xbutton, [ENTER] button, and ?/1 button
simultaneously.
2. The fluorescent indicator tube becomes blank for a while, and
the set is reset.
[GC TEST MODE]
•This mode is used to check the fluorescent indicator tube,
LEDs, keys, VOLUME jog, OPERATION DIAL jog, AMS
jog, destination, software version and VACS level.
Procedure:
1. Press xbutton, [ENTER] button and [DISC 2] button-
simultaneously.
2. All LEDs and segments in fluorescent indicator tube are lighted
up. All LEDs are lighted up in red color.
3. When you want to enter the software version display mode,
press [DISC 1] button. The model is displayed.
Press [DISC 1] button again to show destination.
4. Each time [DISC 1] button is pressed, the display changes from
MC version, GC version, SYS version, CD version, CDDM
version, CDMA version, CDMB version, BDA version, BDB
version, ST version, TC version, TA version, TM version in
this order, and returns to the MC version display.
5. When [DISC 3] button is pressed while the version numbers
are being displayed except model and destination, the date of
the software creation appear. When [DISC 3] button is pressed
again, the display returns to the software version display. When
[DISC 1] button is pressed while the date of the software
creation is being displayed, the date of the software creation
is displayed in the same order of software version display.
6. Press [DISC 2] button, the key check mode is activated.
7. In the key check mode, the fluorescent indicator tube displays
“K 0 V0J0”.
Each time a button is pressed, “K” value increases. However,
once a button has been pressed, it is no longer taken into
account.
“V” value increases in the manner of 0,1, 2, 3 ... if [VOLUME]
knob is turned clockwise, or it decreases in the manner of 0,
9, 8, 7 ... if [VOLUME] knob is turned counter-clockwise.
“J” value increases in the manner of 0,1, 2, 3 ... if [OPERATION
DIAL] knob is turned clockwise, or it decreases in the manner
of 0, 9, 8, 7 ... if [OPERATION DIAL] knob is turned counter-
clockwise.
8. When [DISC 3] button is pressed after all LEDs and segments
in fluorescent indicator tube light up, the fluorescent indicator
tube displays “VACS A+B FAPC”. A is VACS level which is
trigger by signal level, B is VACS level which is trigger by
temperature and C is VACS level which is trigger by APVACS
(Abuse Protection VACS).
F is shown if the fan is turned in high speed and vice-versa.
The signal level, which will trigger VACS A is shown in the
center area of fluorescent indicator tube.
9. When [EX-CHANGE/DISC SKIP] button is pressed after all
LEDs and segments in fluorescent indicator tube light up,
alternate segments in fluorescent indicator tube would light
up. If you press [EX-CHANGE/DISC SKIP] button again, another
half of alternate segments in fluorescent indicator tube would
light up. Pressing [EX-CHANGE/DISC SKIP] button again
would cause all segments lights up.
10. To release this mode, press three buttons in the same manner
as step 1, or disconnect the power cord.
SECTION 4
TEST MODE

18
HCD-GNX780/GNX880
[VACS ON/OFF]
•This mode is used to switch ON and OFF the VACS (Variable
Attenuation Control System).
Procedure:
1. Press ?/1 button to turn the set ON.
2. Press xbutton and [ILLUMINATION] button simultaneously.
The message “VACS OFF” or “VACS ON” appears on the
fluorescent indicator tube.
[TUNER STEP CHANGE]
•The step interval of AM channels can be toggled between 9
kHz and 10 kHz.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Press [TUNER/BAND] button to select the “AM”.
3. Press ?/1 button to turn the set OFF.
4. Press [ENTER] button and ?/1 button simultaneously. The
system will turn ON automatically. The message “AM 9k
STEP” or AM 10k STEP” appears on the fluorescent indicator
tube and thus the channel step is changed.
[CD SERVICE MODE]
•This mode let you move the CD sled motor freely. Use this
mode when you want to clean the optical pick-up.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select CD function.
3. Press x, [ENTER] button, and
Z
OPEN/CLOSE
button
simultaneously.
4. The CD service mode is activated. The message “SERVICE
MODE” appears on the fluorescent indicator tube.
5. With the CD in stop status, press
M
to move the optical
pick-up to outside track, or press
m
to move to inside
track. The message “SLED OUT” or “SLED IN” appears on
the fluorescent indicator tube.
6. To turn on or off the laser, press [DIRECTION] button. The
message “LD ON” or “LD OFF” appears on the fluorescent
indicator tube.
7. To release this mode, press ?/1 button.
[CD AGING MODE]
This mode can be used for operation check of CD section.
•If an error occurs, the aging operation would stops and the
status is displayed.
•If there are no error occurs, the aging operation would
continues repeatedly.
Procedure:
1. Press ?/1 button to turn the set ON
2. Select CD function.
3. Load three discs on the disc tray.
4. Press [PLAY MODE] button on the remote repeatedly to select
the “ALL DISCS” mode, and press the [REPEAT] button on
the remote repeatedly to select “REPEAT OFF” mode.
5. Press x button, [ENTER] button, and [EX-CHANGE/DISC
SKIP] button simultaneously.
6. Aging operation is started.
7. To release this mode, press ?/1 button or disconnect the
power cord to turn the power OFF.
Aging mode sequence:
Start (from disc 1)
Disc chucking
TOC reading
Play first track for 2 seconds
Play last track for 2 seconds
EX-CHANGE open/close
Open the disc tray
Disc skip
Close the disk tray
Change the next disc

19
HCD-GNX780/GNX880
Display
M*$$%%&&##00
3) Display of no disc errors
D*: The number of mechanical error (“00” is latest one)
(Rotate
>
.
knob in the direction of either to display next
error)
$$: Error type
01: Focus error
02: GFS error
03: Setup error
%%: Not used
&&:
00: No disc judgment without chucking retry.
01: No disc judgment after chucking retry.
##: The state when judged as no disc
01: Stop
02: Setup
03: TOC reading
04: Access
05: Playback
06: Pause
07: Manual search (Play)
08: Manual search (Pause)
[CD REPEAT 5 LIMIT OFF MODE]
•The number of repeat for CD playback is 5 times when the
repeat mode is “REPEAT ALL”. This mode enables CD to
repeat playback for limitless times.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select CD function.
3. Press xbutton, [CD] button and [DISC 1] button
simultaneously to enter the CD repeat 5 limit off mode and
the fluorescent indicator tube displays “LIMIT OFF”.
4. To release this mode, operate the cold reset. (Refer to the “MC
COLD RESET”)
[CD SHIP MODE (WITH MEMORY CLEAR)]
•This mode moves the optical pick-up to the position durable
to vibration and clears all data including preset data stored in
the RAM to initial conditions. Use this mode when returning
the set to the customer after repair.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select CD function.
3. Press x button, [SOUND FLASH] button and ?/1 button
simultaneously. The set will power off automatically.
4. After the “STANDBY” blinking display finish, a message
“MECHA LOCK” is displayed on the fluorescent indicator
tube and the CD ship mode is set.
Display
D*$$%%&&##00
• Display when an error occurred (CD Error Code Mode)
Procedure:
1. Press xbutton, [ENTER] button and [DISC 1] button
simultaneously to enter the error code display mode.
2. The fluorescent indicator tube displays the number of total
error.
3. Each time
M
m
knob is rotated, display change as
below.
Display of total error
>+ direction
–.
direction
Display of Mechanical errors
>+ direction
–.
direction
Display of no disc errors
4. To clear the error record, operate the cold reset. (Refer to the
“MC COLD RESET”)
5. To release this mode, press the ?/1 button or disconnect
the power plug to turn the power OFF.
1) Display of total error
Em**: The number of mechanical errors.
Ed **: The number of no disc errors after chucking the disc.
2) Display of mechanical errors
M*: The number of mechanical error (“00” is latest one)
(Rotate
>
.
knob in the direction of either to display next
error)
$$: Not used
%%: Loading related error (Second figure is not used)
D: Stop by the problem other than mechanical problem while
closing.
E: Stop by the problem other than mechanical problem while
opening.
C: Stop by the problem other than mechanical problem while
chucking up.
F: Stop by the problem other than mechanical problem while
chucking down.
&&: Emerging error
01: Stop while chucking up.
02: Stop while chucking up.
03: Time-out of EX-CHANGE open.
05: Time-out of EX-CHANGE close.
##: Not used
Display
Em**Ed**

20
HCD-GNX780/GNX880
[CD TRAY LOCK MODE]
•This mode let you lock the disc trays. When this mode is
activated, the disc tray will not open when
ZOPEN/CLOSE
button or [EX-CHANGE/DISC SKIP] button is pressed. The
message “LOCKED” will be displayed in the will be displayed
on the fluorescent indicator tube.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select CD function.
3. Press xbutton and
ZOPEN/CLOSE
button
simultaneously and hold down until “LOCKED” or
“UNLOCKED” displayed on the fluorescent indicator tube
(around 5 seconds).
[VIDEO/MD SWITCHING]
•This mode let you switch from VIDEO to MD and vice-versa.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select VIDEO function.
3. Press [VIDEO/MD] button and ?/1 button simultaneously.
The function will change to MD. Press the same buttons again
to change from MD to VIDEO.
[TCM OFFLINE MODE]
•This mode prevents set from power off automatically when
TCM is not connected.
Therefore, measurements can be done even when TCM is not
connected during production.
• Procedure:
1. When the system in turned off, press [EQ BAND] button,
[TAPE A/B] button and ?/1 button simultaneously. The
set will power on automatically.
2. The message “TCM OFFLINE” will be displayed on the
fluorescent indicator tube.
[CD SHIP MODE (WITHOUT MEMORY CLEAR)]
•This mode moves the optical pick-up to the position durable
to vibration. Use this mode when returning the set to the
customer after repair.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select CD function.
3. Press [CD] button and ?/1 button simultaneously. The set
will power off automatically.
4. After the “STANDBY” blinking display finish, a message
“MECHA LOCK” is displayed on the fluorescent indicator
tube and the CD ship mode is set.
[CD POWER MANAGE]
•This mode let you switch on or off power supply to the BU
during TUNER function.
• When CD POWER is set to OFF, the power supply to the BU
is cut off during TUNER function. It will increase the time
taken to access CD when function change from TUNER to
CD but it will improve tuner reception.
•When CD POWER is set to ON, the power supply to the BU
is not cut off during TUNER function. It will reduce the time
taken to access CD when function change from TUNER to
CD but it will decrease tuner reception performance.
Procedure:
1. Press ?/1 button to turn the set ON.
2. Select CD function.
3. Press ?/1 button to turn the set OFF.
4. Press xbutton and ?/1 button simultaneously. The set
will power on automatically.
5. The message “CD POWER ON” or “CD POWER OFF” will
be displayed on the fluorescent indicator tube.