Troubleshooting - Casio CPS-130 Service Manual

B
C
B
Filter output: M5218APR-1 pin 1
C
Filter output: M5218APR-1 pin 7
Tone: Piano
Key: A3
Nature of Trouble
No power
No sound at all
Certain keys or switches
do not function
A certain key or switch does
not function
Distorted sound

TROUBLESHOOTING

Faulty Block
Power IC (LA5668N)
Power jack
Power IC (LA5668N)
Power amp (LA4127)
Main clock generator
CPU (CDT109-005)
ROM (HN62414PD25)
Reset IC (S8053ALR)
Key and switch matrix
Key and switch matrix
Power IC (LA5668N)
ROM (HN62414PD25)
CPU (CDT109-005)
— 10 —
D
E
D
Filter output: M5218APR-1 pin 1
E
Filter output: M5218APR-1 pin 7
Tone: Flute
Key: A3
Checkpoint
Pin 2 should have +9 V.
Jack contact.
Pin 6 should have +5 V.
Check output signals of pins 1 and 20.
Check oscillation at pin 105 of CPU.
Pin 6 should receive a trigger pulse when
turning on the power switch.
Check signals DATA, BCLK, WCK1 and LRCK
of pins 107, 109, 111, and 112.
Check address/data bus.
Pin 1 should provide a low level pulse when
the AC adapter is connected.
Open circuit on KO or KI line.
Dust on the con tact.
Check voltages of pins 2 (+9 V) and 6 (+ 5 V).
Check address/data bus.