Does not Operate at All with Power on. Star Micronics LC-200, NX-1020

TROUBLESHOOTING

4.

Repair by Parts Replacement

4-1. Does not Operate at All with Power on

START

+25V, +5V are supplied? *1

YES

RESET signal becomes

HIGH? *2

YES

Crystal waveform is normal? *3

YES

ROM OE signals become

LOW?

YES

Carriage motor abnormal.

NO

NO

NO

NO

DC Power abnormal.

See 4-2. Power Supply

Circuit Abnormal.

Check RESET circuit; replace parts.

Check crystal circuit; replace parts.

1) Replace CPU or ROM.

2) Check relevant circuit.

Check operation.

END

*2 See (2) waveform in item 10 of Chapter 7.

*3 See (1) waveform in item 10 of Chapter 7.

*1 +25V Line

+5V Line

+25V

±

5% Between Pin 1 and Pin 2 of CN1

+5V

±

2.5% Between Pin 4 and Pin 3 of CN1

– 65 –