Sharp XL 1700 Service Manual - Page 37

• Laser failure. Is +7.2V applied to the pin 1 of CNW805 ? Yes Is +5V applied to the cathode side of ZD801 ? Yes XL-1700/1700C Check the PWB pattern between emitter of Q605 and CNP805/ No CNW805. Check the peripheral parts of ZD801,C820 and C821. No Is +5V applied to the pin 64 (VDD) of IC801 ? Yes Is +3.3V applied to the pin 1 (VCC) of IC802 ? Yes Check the PWB pattern between cathode side of ZD801 and pin No 64 of IC801. Check the PWB pattern between collector of Q802 and pin 1 of No IC802. Is 0V applied to the pin 38 (SEL) of IC801 ? Yes No Is approx. 2V applied to the collector of Q801. Yes Check CNP801/CNW801. If it is normal, the optical pickup is faulty. Does the laser come on when pattern cut between pin 8 (SEL) of No IC802 and pin 38 (SEL) of IC801 ? Yes Check the PWB pattern between IC701 and IC801 (BUCK/CCE/ BUS0~3) Check the peripheral parts of IC802 and Q801. If it is normal, the No optical pickup is faulty. • Focus failure. Does the optical pickup move up and down when the disc is removed? Yes Is the following waveform output at the pin 29 (FEI) of IC801 when the disc is set? Yes pin 29 (FEI) pin 33 (FOO) pin 30 (SBAD) Is the waveform shown above input at the pin 30 (SBAD) of IC801? Yes IC802 is faulty. Check as stated in item "FOCUS SERVO SAWTOOTH WAVE No FAILURE". Check the periphery of IC802 and CNP801/CNW801. Is it normal? No Yes The optical pickup is faulty. Check the pattern between pin 12 of IC802 and pin 30 of IC801. No Check the periphery of IC802 and CNP801/CNW801. - 37 -