Kenwood DMC-K3 Portable MD Player Service Manual

Specifications

System: Mini disc digital audio system

Read method: Noncontact optical reading system (semiconductor laser)

Sampling frequency: 44.1 kHz

Audio compression: ATRAC (Adaptive Transform Acoustic Coding)

Number of channels: 2 channels

Frequency response: 20 Hz to 20,000 Hz (± 3 dB)

Wow & flutter: Less than unmeasurable limit (± 0.001% W.PEAK)

Input/Output terminal: Remote control/Phones jack

Rated power output: 9 mW + 9 mW

Power source:

DC IN jack (4-5.1V)
Specially provided AC adaptor
Car battery adaptor (sold separately, DC-C70)
DC 1.5V: Commercially sold AA alkaline battery (LR-6) × 1
DC 1.2V: Specially provided rechargeable battery (NB-150) × 1 (Charging time: About 3 hours)

Battery life (Fully charge, with "PS on" setting ON):

Specially provided rechargeable battery (NB-150) × 1: Approx. 7 hours
Commercially sold AA alkaline battery (LR-6) × 1: Approx. 8 hours (At 0.5mW+0.5mW output, 32 Ω load)
Standard value during continuous use/charging in an temperature of 25°C.
Time of use may vary depending on battery maker, battery type, use environment, and temperature.
Time will be shorter when "PS off" Mode is set.

Dimensions (not including protruding parts):

W: 99 mm (3-7/8")
H: 17 mm (11/16")
D: 75 mm (2-15/16")

Weight (Net):

115g (0.25 lb) not including the accessory rechargeable battery
140g (0.31 lb) including the accessory rechargeable battery

Notes:

KENWOOD follows a policy of continuous advancements in development. Specifications may be changed without notice.
The full performance may not be exhibited in an extremely cold location (under a water-freezing temperature).

Laser Safety Information: In compliance with Federal Regulations, following are reproductions of labels on, or inside the product relating to laser product safety. KENWOOD-Corp. certifies this equipment conforms to DHHS Regulations No. 21 CFR 1040. 10, Chapter 1, Subchapter J. DANGER: Laser radiation when open and interlock defeated. AVOID DIRECT EXPOSURE TO BEAM.

Contents / Accessories

Contents:

SPECIFICATIONS
CONTENTS / ACCESSORIES
CONTROLS
DISASSEMBLY FOR REPAIR
CIRCUIT DESCRIPTION
Top cover
PC BOARD
SCHEMATIC DIAGRAM
EXPLODED VIEW
PARTS LIST

Accessories:

AC adapter (1) (W09-)
Batteries: NB150 (1) (W09-1267-05)
Carrying case (1) (W01-0938-05)
Remotcon (1) (A70-1258-05)
Stereo headphone (1) (W01-)
Stereo headphone (1) (W01-0963-05)

* Refer to parts list on page 17.

Caution

Beware of condensation:

When water vapor comes into contact with the surface of cold material, water drops are produced. If condensation occurs, correct operation may not be possible, or the unit may not function correctly. This is not a malfunction, however, and the unit should be dried. (To do this, turn the POWER switch ON and leave the unit as it is for several hours.)

Be especially careful in the following conditions:

When the unit is brought from a cold place to warm place, and there is a large temperature difference.
When a heater starts operating.
When the unit is brought from an air-conditioned place to a place of high temperature with high humidity.
When there is a large difference between the internal temperature of the unit and the ambient temperature, or in conditions where condensation occurs easily.

Resetting the unit:

This system uses a microcomputer so it may malfunction due to external noise or interference. In such a case, unplug the power cord and remove the batteries, then plug the power cord again and insert the batteries again.

Troubleshooting

Symptom	Cause	Remedy
Unit fails to turn ON.	The disc holder is not securely closed.	Close disc holder securely.
	The battery is depleted.	Charge the battery.
	HOLD status is engaged.	Deactivate HOLD status.
There is no sound.	The volume is at minimum level.	Increase the volume.
	The remote control or headphones are disconnected.	Insert plug securely.
The unit does not respond to key operation.	HOLD status is engaged.	Deactivate HOLD status.
	The battery is depleted.	Charge the battery.
	The remote control or headphone plug is not securely inserted.	Insert plug securely.
Sound skips.	The disc holder is not securely closed.	Close disc holder securely.
	The disc is scratched or damaged or the recording is not good.	Replace the MD.
	The unit is in a place where there is excessive vibration.	Move the unit to a place where there is little vibration or set to "PS off".
Battery does not charge.	You are using commercial rechargeable battery.	Use the special rechargeable battery (NB-150).
	The unit has become hot because of exposure to direct sunlight etc.	Wait until the unit has cooled to normal temperature.
	You are using another AC adaptor than the accessory adaptor.	Use the accessory AC adaptor.
	The AC adaptor has become disconnected.	Connect the AC adaptor securely.

Meaning of display messages:

Message	Meaning	Action
"noDISC"	• There is no MD in the unit. • Nothing is recorded on this MD.	• Insert a MD into the unit. • Replace the disc with a prerecorded MD when playing it back.
"BLANK"	The *UTOC contents are faulty.	Replace the MD.
"ERROR"	• The disc is scratched or damaged, so playback is not possible.	Replace the MD.

*UTOC: A recordable MD has an area for recording so-called UTOC (User's Table of Contents) data. The UTOC contains number of tracks, playing time, written data, and other rewritable information.

Controls

Main Unit

Indicators:

HOLD indicator
Play indicator
Battery indicator
Track number indicator

Controls:

Disc Holder
►►►► (Skip up) key
►/ (Play/pause) key
Hand strap attaching hole
◄◄ (Skip down) key
Battery cover
▲ (Volume up) key
▼ (Volume down) key
HOLD switch
LCD
OPEN slider
DC IN jack (External power jack)
PHONES jack

Remote Control

Controls:

HOLD switch
MODE key
LCD
►►► (Skip up) key
►/ (Play/pause) key
(Stop/off) key
Charge key
(Skip down) key
(Volume down) key
(Volume up) key
PHONES jack

MODE key (Only by remote control operation):

Use this key to set playback-related features and other convenient functions. Please also read "Playback (Application)" and "Convenient functions" for details.

The mode changes each time the MODE key is pressed:

Fast forward/fast reverse (search)
Changing the display mode
Play Mode
Changing the tone (BASS BOOST)
Original display

The mode changes each time the MODE key is pressed:

AUTO PLAY
AUTO POWER SAVE
Operating tone (Beep)
Original display

To change one of the above setups after returning to the original display, restart from the step of pressing and holding the MODE key for more than 2 seconds.

Using the Clip:

Clip the remote control unit to the edge of your bag or pocket.

Disassembly for Repair

How to Remove Case

Remove 7 screws (1).
Slide the case to the opposite side of the battery case (2).

How to Check PCB

Remove 7 screws (3x5, 7x2) and unsolder the corner of pcb (8).
Connect the ground wire to the LCD mounting hardware and the frame of the unit (4).
Fix the switch 1 (ON mode) by the tape (7). And check the unit with standing it.

Circuit Description

1. Main microprocessor: uPD784036GC831 (X33 : IC5)

1-1 Microprocessor periphery block diagram (X33)

[Diagram showing connections between IC5 (u-COM), IC12 (MOTOR DRIVER), IC9 (RE/SERVO), IC7 (DSP/ATRAC), IC8 (BASS BOOST), IC10 (E2PROM), and other components.]

1-2 Pin description

Pin No.	Name	I/O	Description	Function	H/L
1	XLAT	O	DSP IC (CXD2655BR) LATCH signal
2	XRST	O	DSP IC (CXD2655BR) HARD RESET signal
3	XSTBY	O	RF/SERVO IC (CXA2523AR) STAND BY signal
4	LDON	O	PICK UP LASER on/off signal	L: LIGHTING	H: NON LIGHTING
5	BEEP	O	BEEP output/ to HP AMP
6	BASS BOOST	O	Analog bass boost control	L: BOOST ON	H: BOOST OFF
7	RESET	O	µ-com RESET
8	VDD		µ-com +power supply
9	X2	O	µ-com SYSTEM CLOCK_OSC port (out)
10	X1	I	µ-com SYSTEM CLOCK_OSC port (in)
11	VSS		µ-com GND
12	LCD DATA	O	LCD remocon display data serial output
13	BEMFW	I	SLED MOTOR comparator signal(W)
14	BEMFV	I	SLED MOTOR comparator signal(V)
15	BEMFU	I	SLED MOTOR comparator signal(U)
16~18	S1~3	O	SLED MOTOR control signal for DRIVER input port
19	NC	O	-
20	SP	O	SYSTEM POWER port DSP IC (CXD2655BR) RF/SERVO IC (CXA2523AR) Motor Driver/HP amp VCC2 power supply	H: ON L: OFF
21	CHG1	O	Rechargeable circuit control signal (SET UP POWER SUPPLY)	H: RECHARGEABLE L: NORMAL
22	CHG2	O	Rechargeable circuit control signal (START RECHARGEABLE)	H: RECHARGEABLE L: NORMAL
23,24	TEST0,1	I	Test mode setting	TEST1/0 HH: TEST1 HL: TEST2/3 LH: TEST4
25~43	SEG19~1	O	Sets LCD segment output 19~1
44	NC		-
45	VSS		µ-com GND
46	TEST	I	µ-com TEST port (CONNECT GND)
47	COM	O	Sets LCD COMMON
48	EPSK	O	E2PROM CLOCK output
49	PW SW	O	HP amp power supply (CONNECT HP. AMP POWER SUPPLY PORT)	H: ON L: OFF
50	MUTE SW	O	HP amp mute control	L: MUTE ON	H: MUTE OFF
51	PWS	O	DRAM/LCD remocon power supply port	H: ON	L: OFF
52	EPCS	O	E2PROM LATCH signal
53	EPDI	O	E2PROM DATA signal
54	EPDO	I	E2PROM DATA signal
55	VDD		µ-com +power supply
56	KEY0	I	Set's key input	TAKE IN A/D
57	KEY1	I	LCD remocon key input	TAKE IN A/D
58	ADP	I	Adaptor DC detector	TAKE IN A/D
59	CHGOK	I	Rechargeable battery detector	TAKE IN A/D
60	BATT	I	Battery DC input	TAKE IN A/D
61	SEIN(REVERSE)	I	SLED ERROR signal (REVERSE)	TAKE IN A/D
62	SEIN(FORWARD)	I	SLED ERROR signal (FORWARD)	TAKE IN A/D
63	ADON	O	AVREF voltage output
64	AVDD		µ-com A/D power supply
65	AVREF1	I	µ-com A/D reference voltage input
66	AVSS		µ-com A/D GND
67,68	NC	O	-
69,70	AVREF2,3	I	µ-com D/A reference voltage input
71	JTYPE	I		H: EXCEPT JAPAN	L:JAPAN
72	HOLD	I	HOLD SW
73	XINT	I	DSP IC (CXD2655BR) XINT EDGE intercept input	H:
74	SQSY	I	DSP IC (CXD2655BR) ADIP SYNC intercept input	L: EDGE INTERCEPT
75	LID SW	I	LID OPEN SW	H: CLOSE	L:OPEN
76	SCLK	O	DSP IC (CXD2655BR) SERIAL CLOCK input
77	W.UP	I	µ-com WAKU UP input	H:
78	SENS	I	DSP IC (CXD2655BR) SENSE signal	EDGE intercept
79	SRDT	I	DSP IC (CXD2655BR) SERIAL DATA signal
80	SWDT	O	DSP IC (CXD2655BR) SERIAL DATA signal

1-3 Voltage matrix key (u-COM pin 5,5)

SET 6KEY	PIN 56 KEY0	Port voltage [V]	Key function
0	0.4	►/II
1.6	2	2.4	2.8	◄◄
Port voltage [V]	Key function
0	0.21	►/II
1	1.6	1.9	2.23	VOL.UP
2.57	2.8	VOL.DOWN
REMOCON 8KEY PIN 57 KEY1	Port voltage [V]	Key function
	MODE
	HOLD
Non remocon

2. TEST MODE

* Test mode I is required when disassemble or replace the laser pickup and MD mechanism.

* Test mode I and II are required when replace the E2PROM.

* Need the remote control for adjustment procedure.

How to Reset the Unit.

* Connect the AC adapter to the wall outlet with pressing <SKIP> key.

* Contents of initialization:

Volume: VOL 10
Repeat: OFF
Bass boost: BOOST 1
Remocon mode: DISC/TRACK(title mode)
Auto Play: OFF
Resume TNO: TNO[1]
Auto power save: ON
Beep: ON
Display in Remocon: [ENG]
Display in unit: [En]

* Power off after display shows for 2 seconds

2-1 TEST MODE I (Adjusting Mode)

* Contents (to memorize the adjustment result to E2PROM)

EF Balance(automatic/manual)
Focus Bias(automatic/manual)

Note: Automatic adjustment only in this manual

2-1-1 Setting

Connect the #24(P_TEST1) and 23(P_TEST0) ports of IC5 to 2.8v(VDD) port. Next to AC adapter. Mode is STOP.
Press the SKIP UP key. To memorized the proper value of FE balance automatically. Manual adjustment if press the SKIP DOWN key.

2-1-2 Automatic FE Balance and FOCUS Bias Adjustment

The FE balance setting value of the default starts a servo by the value which is memorized in E2PROM. Incidentally, there are 3 kinds of memory area(high/Low reflection Pit/Low reflection groove)which store a balance setting value E2PROM. At the time of automatic adjustment this 3kinds of areas are used appropriately according to a disc.
There is a setting range of 32 steps(00h-1Fh) in the balance setting value. The default value are High reflection 51h (pit), Low reflection 10h (groove), Low reflection 90h (groove).
Display shows the following if automatic adjustment proceeds. Remote cont [WAIT 0] --- O means in operation mode. Unit [01]
Adjustment is over if loading the pre recorded disc. In case of the recordable disc, the servo will be "03" mode. Read the TOC in lead area and read the head-er and access lead -in area in CPLAY mode. Remote cont [WAIT O] Unit [01]
Proceed pit area adjustment after TOC read if loading the recordable disc. Change to focus bias check after TOC read if loading the pre recorded disc. Remote cont [WAIT O]
Change to FOCUS Bias step after pit area adjustment if loading the recordable disc. Remote cont [WAIT O] Unit [01]

2-1-3 Focus Bias Check

The Focus bias will be adjusted automatically at the focus bias points(+16,0,-16)
Remote cont [*80 00] left 2 figures: bias setting value +80h right 3 figures: C1 error rate(OVR;4 figures)
Display shows setting value+80h. Press the PLAY/PAUSE key to stop Automatic Adjustment.

2-2 TEST MODE II (AUDIO SPEC)

* Item of audio specification(use test disc TDYS1)

Reference TNO[ 2]: 1kHz sinewave, 0dB,L &R, Emphasis off
Frequency Response TON[ 3]: 40Hz sinewave,0dB,L&R,Emphasis off
Modulation Noise TON[ 6]: 20kHz sinewave,0dB,L&R,Emphasis off
Noise Ratio TON[ 7]: 40Hz Infinity Zero,- dB,L&R,Emphasis off
Channel Separation TON[ 8]: 1kHz sinewave,0dB,L,Emphasis off
Channel Separation TON[ 10]: 1kHz sinewave,0dB,R,Emphasis off
Deemphasis TON[ 13]: 16kHz sinewave,-9.04dB,L&R,Emphasis on

2-2-1 Procedures

Connect #23(P_TEST0) of IC5 to 2.8V(VDD) and #24(P_TEST1) of that to GND. Next Connect AC adapter to the unit. (the unit will be in CPLAY mode after TOC reads) Remocon [TEST 4] Unit [04]
The unit will be in CPLAY after TOC reading. Remocon [TOC OK] Unit [04]
Choose and playback TNO-02 on the disc by PLAY/PAUSE key Remocon [02] Unit [04] playback TNO
Choose and playback every TNO in the above table by PLAY/PAUSE key. TNO will be chosen TNO 02 if repressing the PLAY/PAUSE key after STOP key pressed, Remocon [03] Unit [04] playback TNO

PC BOARD (Component side view)

[Diagram of the PC Board (Component side view) with various components labeled.]

Refer to the schematic diagram for the value of resistors and capacitors.

Schematic Diagram

[Schematic Diagram of the Kenwood DMC-K3.]

Exploded View (Mechanism)

[Exploded view diagram of the mechanism of the Kenwood DMC-K3, showing individual parts and their assembly.]

Parts with exploded view numbers larger than 700 are not supplied.

Exploded View (Unit)

[Exploded view diagram of the unit of the Kenwood DMC-K3, showing individual parts and their assembly.]