Casio CTK-50 Service Manual

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Q101
2SD1858Q,R
R116
D102
MTZ6.2A
R101
D103
LED101
D101
ON
Power Switch
VDD (+5.5 V)
VC (+9 V)
DC +9 V
Input
DG AG
DG
DG AG
C102
R115
R114
OFF
Q102
2SC1740SQ
D201
R208
AVDD (+4.8 V)
POWER SUPPLY CIRCUIT
The power supply circuit regulates two constant output voltages VDD (+5.0 V) for the CPU and the oscilla-
tor, and AVDD (+4.8 V) for the analog circuit.
TROUBLESHOOTING
Nature of Trouble Faulty Block Cause/Remedy
No power Power supply circuit Faulty Q101. Replace Q101.
Faulty D102. Replace D102.
Power switch Poor contact. Clean the contacts.
Power jack (J101) Open J101 or poor soldering. Replace
J101 or resolder.
No sound at all Power Amp (IC101: LA4598) Open or shorted IC101. Replace IC101.
CPU (LSI201: MSM6387-13) Faulty LSI201. Replace LSI201.
Oscillator Faulty Q301. Replace Q301.
Open X301. Replace X301.
Certain keys or switches Key and switch matrix Open circuit on KO or KI line.
do not function Replace keyboard PCB assembly.
CPU (LSI201: MSM6387-13) Faulty LSI201. Replace LSI201.
A certain key or switch Key and switch matrix Dust on the contact.
does not function

Casio CTK-50 Specifications

General

Brand	Casio
Model	CTK-50
Category	Synthesizer
Language	English