SONY UP895
Manual de Servicio

5-2. Print is Too Dark or Too Light
START

Is reference voltage input to pin 2 of IC6 on MA-99 board when �CONTRAST� is set to center position? YES

NO

Peripheral circuits Q200 and Q16 on MA-99 board are defective.

Is reference voltage input to pin 5 of Q7 on MA-99 board when �BRIGHT� is set to center position? YES NO

Peripheral circuits Q16 and RV6 on MA-99 board are defective.

Is voltage (approx. 1.5 to 2.5 V) available at pin 6 of IC304 on MA-99 board when head is at the normal temperature? YES

Peripheral circuit IC401 and pins 29 and 30 of CN9 NO on MA-99 board, or the thermistor in the head are defective.

Are required voltages available at each terminal, 3 V at pin 19 of IC500 on MA-99 board, and 1 V at pin 23 of IC500? YES

Peripheral circuit Q21 on MA-99 board is defective. NO

The head voltage or CN9 on MA-99 board is defective. Is density of stair step printed in test mode properly? NO

YES

The data buses of IC500 and IC503 on MA-99 board are defective.

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UP-895/(E)