Sharp XL-DH20NH

XL-DH20NH
6 – 2
( 1 ) Focus error system check.
Although a CD is inserted and the cover is closed,
" NO DISC " is displayed.
No Check incoming jack supply AC ( 220V ).
Yes
2. Is it Open / Close function OK ? No Check incoming power supply VCC ( +3.3V )
Yes
3. Is Sled able to move to inner ? No Check Sled circuit, U304 ( Pin 28 ).
Yes
4. Is the laser lit ? No Check SLE circuit, CD Laser circuits.
Yes
5. Does the focus ( lens ) move up and down ? No Check U302 ( Pin 109, 3 ,4 ) and U304 ( Pin 1, 28 ).
Yes
6. Is the turntable rotating ? No Check U302 ( Pin 2 ) and U304 ( Pin 26 ).
Check Spindle SLED circuit.
Yes
7. Is it the CD Laser driver circuit OK ? No
Check the CD Laser driver ( Q206, Q302, Q303 )
peripheral circuit.
( 2 ) Audio do not operate normally
The RF waveform is normal and the time is
displayed normally, but no sound is produced.
Or the sound has dropouts.
1. Put a disc on DISC compartment.
Yes
2. When playback starts does the disc initialise ? No Repeat steps as Focus errror system check occurred.
Yes
3. Are the RF signal level output from U302
No Is the objective lens of optical pickups clean ?
pin no 21 and 33 ( 3.3V and 1.8V ) normal?
( Waveform drawing Figure 1 for CD )
Yes
Yes
4. Replace Servo PWB. No Replace optical pickup mechanism unit.
Yes
1. Does the servo supply is + 3.3 V?