Troubleshooting - Casio JD-8000 Service Manual

9. TROUBLESHOOTING

1. Intermittent display
Is the Heat seal defective ?
Is the battery contact weak ?
Are there short circuit around the pins
of the LSI (HC3000-08-F1) ?
Is the soldering weak ?
Replace the Z808-1 PCB ass'y.
2. Erratic display
Is the Heat seal defective ?
Is the LCD defective ?
Are the voltage V0 ~ V4 OK ?
Are there short circuit around the pins of the
LSI (HC3000-08-F1) or between the pins of
the crystal oscillator (·2) ?
Are there short circuit around
the pins of the RAM and ROM ?
Replace the Z808-1 PCB ass'y.
START
N
N
N
N
START
N
Y
N
Y
N
N
— 22 —
Y
Replace
Y
Clean and adjust pressure of contact
Y
Resolder
Y
Resolder
Y
N
Y
Y
Replace
Replace
Check or replace the chip
capacitors C4 ~ C8
Resolder
Resolder