Casio EG-5 Service Manual
EG-5
INDEX
(without price)
ELECTRIC GUITAR
CONTENTS
Specifications.................................................................................... 2
Block Diagrams................................................................................. 3
Disassembly Instructions ................................................................ 5
Tuning ................................................................................................ 6
Adjustment ........................................................................................ 7
Circuit Description ............................................................................ 8
Wiring Diagram.................................................................................. 9
Schematic Diagrams....................................................................... 10
Exploded View................................................................................. 14
Parts List.......................................................................................... 15
SPECIFICATIONS
GENERAL
Body: Inner; Die cast aluminum
Outer; High impact PS resin
Neck: Hard maple
Pickup: CASIO original
Guitar controls: Main Volume, Guitar Mix, Guitar Volume, Distortion ON/OFF, Distortion Drive
Tape recorder: Recording system: Stereo
Playback system: Stereo (monaural speaker and monaural guitar output)
Tracks: 4-track, 2-channel stereo
Tape type: Normal
Tape speed: 4.76 cm/sec.
Fast forward/reverse time: approximately 150 sec. (C-60)
Recording level: Auto (automatically adjusted to prevent distortion)
Basic functions: REC, PLAY, F.FWD, STOP/EJECT, PAUSE
Other functions: Tape pitch adjustment (+/-3%), Auto stop
Built-In speaker: 10 cm dia. 2.0 W input rating: 1 pce.
Terminals: Line In Jack [stereo mini jack, input impedance: 15 ohms]
Guitar Out Jack [monaural standard jack, output impedance: 4.5 ohms,
output voltage: 0.25 V (RMS) Maximum]
Phones Jack [Stereo mini jack, output impedance: 4.5 ohms,
output voltage: 0.50 V (RMS) Maximum]
AC Adaptor Jack (DC 9 V)
Power source: DC: 6 AA size dry batteries
Battery life: Approx. two hours (R14P/SUM-2)
Approx. four hours (LR14/AM2)
AC: AC Adaptor AD-5
Power comsumption: 7.7 W
Dimensions (HWD): 75 x 966 x 324 mm
(2-15/16 x 38-1/16 x 12-3/4 inches)
Weight: 3.2 kg (7.0 lbs) including batteries
ELECTRICAL
Current drain with 9 V DC:
No Sound Output 92 mA ± 20%
Maximum volume 750 mA ± 20%
Speaker Output Level (Vrms with 8 ohms load)
with 6th string picked at 12th fret from 5th string 780 mA ± 30%
Phone Output Level (Vrms with 8 ohms load)
with 6th string picked at 12th fret from 5th string 65 mA ± 30%
Guitar Output Level (Vrms with 8 ohms load)
with 6th string picked at 12th fret from 5th string 32 mA ± 30%
Minimum Operating Voltage: 6.3 V
— 2 —
Pickup
Distortion
Button
HOT1
HOT2
Hum
Cancel
VR13
Guitar Volume
Flip-Flop
T51, T52
VR11
Distortion
Changeover
T54, T55
Filter
IC53
Distortion
Circuit
VR51
Distortion Volume
Mixer
IC53
Guitar MIX
VR52
— 3 —
Cassette Mechanism
Head Head Amp.
Leaf Switch
Motor
Line IN
SVC
+
A
B
BIAS
L-CH
R-CH
REC
Switch
S41
VR31 VR32
Line IN Amp.
MVC (Motor Drive Signal)
T21, T22
Bias Circuit
TA8142AP
IC41
Tape Speed Volume
RAUX
LAUX
T41, L41
Mute
T45, T46
T42
Mute
T43, T44
GUITAR-R
TAPE-R
AUX-R
GUITAR-L
TAPE-L
AUX-L
Mixer R
IC42
Mixer L
IC42
BLOCK DIAGRAMS
A
B
Headphone Amp.
Main Volume
A
VR53
RVOUT
LVOUT
Mixer
IC12
LA4525 IC21
Power Amp.
LA4127 IC13
B
Phone Output
Speaker
— 4 —
DC IN 9V
VC 9 V
Power Switch
S21
Power Supply Circuit
< DISTORTION CIRCUIT >
Band-Pass Filter
IC51
VCC 9 V
D22, T24
Amp.
IC51
Distortion Volume
VR51
+
Amp. Clipper
IC52
Mute
T23
DI505~DI508
T56
Guitar Output
Filter
IC52
DISASSEMBLY INSTRUCTIONS
Note: EG-5 has a detachable neck. So do not loosen the four black screws attaching the neck to the body at
usual repairs. Only when replacing the neck, remove the screws.
Black Screws
< Figure 1 >
To open the lower body
1. Remove the battery cover.
2. Remove the eighteen screws holding the lower body.
3. Open the lower body.
To disassemble the cassette mechanism
1. Open the lower body.
2. Desolder PC cable, JD cable and PH cable on JCM370-MA4M PCB.
3. Remove three screws on JCM370-MA2M PCB and four screws on JCM370-MA4M PCB.
4. Remove all buttons from the cassette mechanism.
5. Remove the four screws holding the cassette mechanism.
6. Remove the cassette mechanism from the upper body.
To disassemble the pickup
1. Remove all strings from the guitar.
2. Open the lower body.
3. Desolder the cable of the pickup on JCM370-MA1M PCB.
4. Remove two black screws on the upper body.
To disassemble the bridge
1. Remove all strings from the guitar.
2. Remove four screws on the bridge.
To disassemble the neck
1. Remove all strings from the guitar.
2. Remove the four black screws on the lower body.
— 5 —
TUNING
Most guitar players tune their guitar by themselves as they like.
Do not adjust tunings of a customer’s guitar at usual repairs, because the tunings may be re-adjusted by a
customer. Only after replacing the neck, the bridge or the pickup, adjust a certain tuning item shown in the
following table.
Items to be tuned Replaced Part
Warp of neck Neck
Pickup height Pickup
String height Bridge
Octave pitch Bridge
Tools/Equipments required
4 mm hexagon key (Accessory tool)
1.5 mm hexagon key (Accessory tool)
Guitar tuning meter
TUNING PROCEDURE
Please refer to the tuning instructions in the operation namual also.
To adjust warp of neck
1. Check the space between a string and the 10th fret when pressing the string at the 1st fret and at the 19th
fret.
And check all strings.
2. If the space exceeds 0.3 mm, straighten the neck by turning the nut in the head clockwise with a 4 mm
hexagon key.
To adjust pickup height
1. Press a string at 22nd fret.
2. Use a screw driver, adjust a height of the pickup to be 2 mm off from the string by turning two screws at both
ends of the pickup.
To adjust string height
1. Use a 1.5 mm hexagon key, adjust a height of the 1st string to be 2 mm above the 14th fret by turning two
hexagon socket screws at the 1st saddle in the bridge.
2. Adjust height of other strings by the same way.
To adjust octave pitch
1. Use a guitar tuning meter, tune the 1st string at open string to the standard pitch.
2. Use a guitar tuning meter, compare pitch of two tones, a tone at the 12th fret with a harmonic*.
3. If pitch of the tone at the 12th fret is sharper over 3 cents than pitch of the harmonic tone, turn the adjustment
screw clockwise.
4. If pitch of the tone at the 12th fret is flatter over 3 cents than pitch of the harmonic tone, turn the adjustment
screw counterclockwise.
5. Repeat steps 1 to 4 until the differnce of pitch between two tones is within 3 cents.
6. Adjust octave pitch of other strings.
* Harmonic: An overtone produced by touching a string above the 12th fret with a finger and by picking the
string just before freeing the string.
— 6 —
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