Casio LD-50 User manual

ELECTRONIC DRUM
LD-50
AUG. 2001
LD-50

— 1 —
SPECIFICATIONS
GENERAL
Percussion Pads: 4 (with touch response)
Lighting Guide System: Lesson, Dual Light, Synchro
Sounds: 47 assignable percussion sounds + 20 assignable sound effects
Display: MAIN VOL., RHYTHM VOL., TEMPO, LIGHT, PLAY LEVEL, RHYTHM,
SE SET, DRUM SET, ASSIGN, EFFECT, U1/U2 indictors; note icon; mute
icon; low battery icon; dial icon; drum animation
Main volume: 10 levels
Rhythm volume: 10 levels
Rhythms: 50
Demos: 1
Auto Percussion Set: In accordance with rhythms and demo
Preset Percussion Sets: 7
User Percussion Sets: 2 (Cleared by power off.)
Play Level: Rhythm or Demo (during Lesson or Dual Light mode in Auto Percussion
Set)
Tempo: ±50 levels from default value of selected rhythm or demo
Effects: 3 types (for percussion sounds only)
Sound Effects: 4 x 5 sets
Rhythm Controllers: START/STOP, SYNCHRO START, TEMPO
Speaker: 10 cm diameter (Output: 3.0W)
Dial: Controls Main Vol., Rhythm Vol., Tempo, Light, Play Level, Rhythm, SE
Set, Drum Set, Assign, and Effect settings.
I/O Terminals: Power Supply: DC 9V jack
Headphones/Output: Stereo standard jack (Output is monaural.)
Output impedance: 220Ω
Output voltage: 3.5V (RMS) MAX
Power Supply: 2-way AC/DC power sources;
Batteries 6 AA-size
Battery life approximately 5 hours on LR6 (AM3) alkaline
batteries
AC adaptor AD-5
Power Consumption: 9 V 7.7 W
Dimensions: 49.5 x 28.0 x 17.0 cm (19 8/16" x 11 5/16" x 6 11/16")
Weight: Approximately 2.0 kg (4.4 lbs) (without batteries)
* Designs and specifications are subject to change without notice.
CONTENTS Page
SPECIFICATIONS .................................................................................................................................... 1
BLOCK DIAGRAM .................................................................................................................................... 2
CIRCUIT DESCRIPTION .......................................................................................................................... 3
TROUBLE SHOOTING ............................................................................................................................. 8
PCB LAYOUT ........................................................................................................................................... 9
EXPLODED DRAWING .......................................................................................................................... 14
PARTS LIST............................................................................................................................................ 15
SCHEMATIC DIAGRAM ......................................................................................................................... 17

— 2 —
BLOCK DIAGRAM
LCD
Keyboard
power
switch Power Supply Circuit
3IC2 3IC4 3T4
PAD Sevsor
PAD LED
2T3.2T10.2T11.2T12
LCD Driver
S6A0069
6IC 1
LSI MIDI
SAM9793
1IC112
sound effect
HE 80085
1IC11
oscillator
xtral2 12MHZ oscillator xtral1 9.6MHZ
DAC
PCM 1717
1IC1
Vol.Ctrl
M62429
1IC2
Power Amp
LA4550
3IC1
LPF
1R2~1R7 1R25
1C22~1C26
MCU
P87C52
1IC4
DFF
74HC374
1IC7~1IC10
MIDI Rom
HE80M04
1IC5
A0~A18 MIDI
DB4~DB7
KSR/WE
Audiobus
Audio ch2
Audio ch1
Mclk
ML
MC
MD
com1~com16
SEG1~SEG40
D0~D7 reset
reset
PWN-WRN
VCC VLED
DC+9V
BATT DC+9V IN
D+5 A+5
D.LE.clk
D.CLK
Headphone speaker
OE
key0~key3
sel0~sel4
4
4

— 3 —
Pin. No. Terminal In/Out Function
CIRCUIT DESCRIPTION
Power Amplifier (LA4550)
The power amplifier is a two channel amplifier which connected in BTL mode. The following table shows the
pin function of the LSI.
1
2
3
4
5
6
7
8
9
10
11
12
G0
G1
NC
OUT2
BS2
NF2
IN2
DC
PREGND
IN1
NF1
BS1
OUT1
VCC
PWGND
TAB
Not used
Channel 2 Output
Terminal for a bootstrap capacitor
Negative feedback input
Channel 2 Input
Terminal for a decoupling capacitor
Ground (0V) source
Channel 1 Input
Negative feedback input
Terminal for a bootstrap capacitor
Channel 2 Output
+9V source
In Ground (0V source)
In Ground (0V source)
---
Out
---
In
In
---
In
In
---
Out
In
GND
GND

— 4 —
LCD DRIVER (S6A0069)
The LCD driver can drive a dot matrix LCD having 40 segment and 16 common lines. The LSI contains 240
graphic symbols in the built-in character generator ROM, and stores 80 characters in the built-in display data
RAM. In accordance with command from the CPU, the LSI I capable of displaying up to 16 characters
simultaneously. The following table shows the pin function of the LSI.
Pin. No. Terminal In/Out Function
1 ~ 22,
63 ~ 80
23
24 ~ 25
26 ~ 30
31 ~ 32
33
34
35
36
37
38
39 ~ 42
43 ~ 46
47 ~ 62
SEG1 ~ SEG40
GND
OSC1, OSC2
V1 ~ V5
CLK1, CLK2
VDD
M
D
RS
R/W
E
DB0 ~ DB3
DB4 ~ DB7
COM1 ~ COM16
Segment signal output
GND (0V) source
Terminal for the built-in clock pluse generator.
The external resistor connected determines the oscillation
frequency.
Bias voltage level for LCD driving
Not used. Connected to extension driver clock
DVDD (+5V) source
Not used. Connected to extension driver.
Not used. Connected to extension driver.
Register selection Input. RS= "High". Data register is
selected. RS="Low", Instruction register is selected.
Read/Write selection Input. When R/W=High, read opera-
tion. When R/W=Low, write operation.
Read/Write enable signal.
Not used. Conencted to GND (0V)
Data Bus.
Common signal/output. Pin 54 (COM8) and Pin 62
(COM16) are not used.
Out
---
In/Out
In
---
---
---
---
In
In
In
---
In/Out
Out

— 5 —
Out
Out
---
---
In
In
Out
---
Out
In
In
---
---
In
In
In
---
---
---
In
In
In
---
Sound Engine (Dream SAM9773)
The sound engine read MIDI message from the MCU and convert them into digital audio data to the external
DAC of sound drum output. The following table shows the pin function of the LSI.
Pin. No. Terminal In/Out Function
1
2
3, 4, 12, 13, 15,
24 ~ 26, 28 ~
42, 44, 50, 53,
59 ~ 66, 69,
71, 72, 74, 75,
77 ~ 79, 81 ~
83,
5, 7, 14, 18, 19,
21, 48, 54, 58,
67, 84, 86
6, 16, 46, 57,
76, 85, 94
8
9
10
11
17, 20, 22, 23,
55
27, 52, 56, 80,
86
43
45
47
49
51
68, 70, 73, 92,
93, 95, 97, 100
87
88, 89
90
91
98
99
CLBD
CKOUT
NC
GND
VCC
DACSEL
DABD0
DABD1
WSBD
Test0 ~ Test4
VC3
IRQ
MIDI OUT
WR
CS
RD
D0 ~ D7
LFT
X1, X2
RESET
PDWN
MIDI IN
RUN
Digital Audio Bit clock
Buffered X2 output Terminal
Not used. (No connection)
Terminals connected to Digital Ground
Terminals connected to +3V source
DAC type selection Input terminal. DAC = 0: 12S, 16 to 20
bits; DAC = 1: Japanese 16 bits.
Digital audio main stereo output terminal.
Not used. Auxillary digital stereo output terminal.
Surround or 3DMIDI output.
Digital audio left/right select.
Test Pins that should be grounded.
Terminals connected to nominal +2.7V source.
Not used. Terminal for indicated that a MIDI byte is avail-
able for read on D0 ~ D7.
Not used. Serial TTL MIDI Output terminal.
D0 ~ D7 data write control terminal.
Chip select, active low.
D0 ~ D7 data read control terminal.
Not used. 8-bit di-directional bus under control of CS, RD,
WR
PLL external RC network.
Terminal connected to 9.6Mhz crystal.
Reset Input terminal, active low.
Power-down, active low. When power-down is active, then
all output pins will be floated. The crystal will be stopped.
To exit from power-down, PDWN should be high and
RESET applied.
Serial TTL MIDI Input terminal.
Not used. Terminal indicates that the synthesizer is up and
running.

— 6 —
MCU (87C58UBA)
The MCU controls all key and button output, sound output, LCD display. It read data from the external ROM
when a drum pad is hit and the selected tone; the MCU can read rhythm data simultaneously when a rhythm
pattern is selected. Then it convert the data into MIDI message and send to the sound engine for sound output.
The following table shows the pin function of the LSI.
Pin. No. Terminal In/Out Function
1
2~5
6~9
10
11
12
13
14
15
16
17
18
19
20, 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36~43
44
NC
PAD4_HIT~
PAD1_HIT
KI0~KI3
#RST
LCD-CK
NC
MIDI-OUT
N.U.
SE-LE
VOL-CK
DATA
CLK
DA-ML
XTAL1, XTAL2
VSS
NC
RESET
N.U.
PWR-WRN
MOE
LEL
LEH
CTR-LE0
CTR-LE1
#PSEN
ALE
NC
#EA/VPP
P0.7~P0.0
VCC
Not used. No Connection.
Input Terminals for Piezzo electric sensor.
Terminals for key scan signal.
Reset signal input.
Clock for LCD Driver chip
Not used. No Connection.
MIDI message output terminal
Not used.
Sound Effect LE signal output terminal.
Clock for Electronic Volume Control chip
Data bus for SE chip, DAC and Electronic volume control
chip.
Clock output for SE chip, DAC and Electronic volume
control chip.
Signal ML for DAC
Connected to 12.0MHz crystal
Ground (0V) source
Not used. No Connection.
Reset signal output
Not used.
Power Warning signal Input Terminal
OE signal for MIDI data ROM
Latch output for the low byte address
Latch output for the high byte address
Latch output for the low byte address
Latch output for the high byte address
Program Store Enable
Address Latch Enable
Not used. No Connection.
Extenal Access Enable
Data I/O
+5V source
---
In
In
In
Out
---
Out
---
Out
Out
Out
Out
Out
---
In
---
Out
---
In
Out
Out
Out
Out
Out
Out
Out
---
In
In/Out
In

— 7 —
Sound Effect Chip (HE80085)
The Sound effect chip read sound data from the built-in ROM in accordance with the pressed SE key (or hitting
the drum pad) and the selected tone. Then it provide the sound waveforms to the Power amp. For sound output,
by converting the data into waveforms with the built-in DACs and Op-Amp. The following table shows the pins
functions of the LSI.
Pin. No. Terminal In/Out Function
1~7, 9~12, 14,
16~18, 20~23,
25, 28~37
8
13
15
19
24
26
27
38
---
VO
#RST
FXI
VDD
CLK
LE
DATA
GND
Not Used.
Voice Output treminal
Reset signal in treminal
External fast clock pin. Connect to RC to generate system
clock.
+5V source
Data clock
Latch Enable
Data bus
Ground (0V) source
---
Out
In
---
In
In
In
In
In

— 8 —
TROUBLE SHOOTING
Nature of Trouble Faulty Block Cause/Remedy
No Power Power supply circuit Faulty 3IC2, 3IC4.Replace 3IC2, 3IC4
Faulty 3T4. Replace 3T4.
Faulty 3D1~3. Replace 3D1~3.
Power switch Poor contact. Clean the contacts.
Power (DC in) jack Open or poor soldering. Replace the
jack or resolder.
No Sound at all Power Amp. Faulty 3IC1. Replace 3IC1
CPU Faulty 1IC4. Replace 1IC4.
Electronic Volume control Faulty 1IC2. Replace 1IC2.
Oscillator Faulty XTAL2. Replace XTAL2.
No music Sound Engine Faulty 1IC12. Replace 1IC12.
CPU Faulty 1IC4. Replace 1IC4.
DAC Faulty 1IC1. Replace 1IC1.
Oscillator Faulty XTAL1. Replace XTAL1.
I/O buffer Faulty 1IC7, 1IC8. Replace 1IC7, 1IC8.
MIDI ROM Faulty 1IC5. Replace 1IC5.
No drum pad sound Piezzo sensor Faulty piezzo sensor. Replace piezzo
sensor.
Cable Check cable.
I/O buffer Faulty 1IC9. Replace 1IC9.
No sound effect Sound Effect Chip Faulty 1IC11. Replace 1IC11.
Certain key or switch do not Key and switch matrix Dust on the contact.
function I/O buffer Faulty 1IC10. Replace 1IC10.
CPU Faulty 1IC4. Replace 1IC4.
LED on drum pad do not Drum pad LED Faulty LED. Replace LED.
light Cable Check cables.

— 9 —
PCB LAYOUT
DIGITAL PCB
Top View
Bottom View

— 10 —
POWER/AMP PCB
Top View

— 11 —
JACK/SW PCB
Top View

— 12 —

— 13 —
LED PCB
Top View

— 14 —
EXPLODED DRAWING
113
20
19
12 15 17
18
14
3
4
5
6
7
8
9
10
11
2
16

Notes: This parts list does not include the cosmetic parts, which
parts are marked with item No. "R-X" in the exploded
view.
Contact our spare parts department if you need these
parts for refurbish.
1. Prices and specifications are subject to change with-
out prior notice.
2. As for spare parts order and supply, refer to the
"GUIDEBOOK for Spare parts Supply", published
seperately.
3. The numbers in item column correspond to the same
numbers in drawing.
PARTS LIST
LD-50

PARTS PRICE LIST
LD-50
NItem Code No. Part Name Specification QPrice Code R
N1 10076480 CABINET/UPPER 8CA-130-05002000 1BD C
N2 10076481 PAD ASSY/DRUM 8CA-130-05001000 1AV B
N3 10076482 LENS/DRUM PAD ##073-05003000 4AU C
N4 10076483 SPACER/A/DRUM LENS ##073-05007000 2AE C
N5 10076484 REFLECTOR ##073-05004000 4AJ C
N6 10076485 RETAINER/REFLECTOR ##073-05005000 4AF C
N7 10076486 CAP/POWER SWITCH ##073-05013000 1AA B
N8 10076487 PCB ASSY/JACK 8CA-120-05003000 1BD A
N9 10076488 PCB/POWER AMP 8CA-120-05002000 1BP A
N10 10076489 CABINET/LOWER 8CA-130-05003000 1BD C
N11 10076490 COVER/BATTERY 8CA-130-05004000 1AB B
N12 10076491 SPACER/B/DRUM LENS ##073-05008000 2AE C
N13 10076492 CAP/JOG DIAL ##073-05010000 1AH B
N14 10076493 KEYPAD/SE ##072-05002000 1AM B
N15 10076494 KEYPAD/FUNCTION ##072-05001000 1AH B
N16 10076495 UNIT/LCD 8CA-120-05005000 1BF A
N17 10076496 PCB/ENCODER 8CA-120-05004000 1AM A
N18 10076497 PCB/MAIN 8CA-120-05001000 1DJ A
N19 10076498 SPEAKER ##056-10854000 1AS B
N20 10076499 BRACKET/SPEAKER ##073-05006000 1AE C
N10075720 STICK/DRUM ##073-05016000 1AX B
- 16 -

— 17 —
SCHEMATIC DIAGRAM
DIGITAL PCB

— 18 —
LED Driver/Pre Process PCB

— 19 —
Power/Amp PCB