SHARP DV720S
Service Manual

FLOW CHART NO.14 FLOW CHART NO.18
No Yes not function.)

PC 2.5V not output.(PC 3.3V(1), (2) is possible) The [No Disc] indication. (In case focus servo does

Is voltage supplied at pin(1) of IC9004? Check the secondary circuit, AT 5V line.

Yes Is focus control signal output to pin(14) of No Check the IC401 DAC power source periphery

Is voltage 2.5V sent out from the pin(2) of Check for load circuit short-circuiting or leak. IC401? circuit. If it is normal, replace IC401. IC9004? Yes Yes the IC702 and IC401. Check IC9004 periphery circuit. Replace IC9004. input into the pin(23) of IC702? Yes

No Is from pin(14) of IC401 No Check the focus control signal (DA0) line between

FLOW CHART NO.15 Check PC 8V line.

The disc tray cannot be opened and closed. No (For remote is possible.) focus control drive output from No Is 8V voltage applied to the pin(8) of IC702? pins (17) and (18) of IC702? No Yes

Dose "L" pulse inputted into pin(13) of Check the S5004 and OPEN/CLOSE KEY line. IC8201, when the OPEN/CLOSE button is Replace IC702. activated on the DVD? No terminal of focus actuator? actuator. Are "L" pulse outputted from the pin(10) of Replace IC8201. Yes IC8201? Check the connection of optical pickup cable. If it is normal, replace the optical pickup.

Yes Is control drive voltage applied to No Check line between IC702 and the focus

Yes

Are "L" pulse inputted into pin(11) No Check line between pin(106) of IC504 and the IC8201? pin(11) of IC8201. (Check the TRAY ACK line and Q8202.) FLOW CHART NO.19

Yes The [No Disc] indication. (When the laser beam

See FLOW CHART NO.16<The disc tray cannot be opened and closed.> does not light.)

FLOW CHART NO.16 Check line between pin(150) of IC401 and Is the Q301(LD POWER ON) drive signal No
No Check line between pin(45) of IC302 and Is Q307(LD POWER CTL) drive output to the No Yes

The disc tray cannot be opened and closed. base Q301 through Q304. (VOSCON) output to the pin(150) of IC401?

15
No (11) and (9) of terminal? pickup terminal. No Check line between IC702 and Yes Is loading motor drive voltage applied to the

Is from pins(70) and (69) IC504 No Check LD-RVS/FWD signal line between IC702 the base Q307. pin(45) IC302? (Checking of symptom.) input into pins(1) (28) of IC702? and the IC504. Yes

Check Is 5V voltage applied to emitter of Q301 and the A_5V line.

loading motor drive output from Is 8V voltage applied to the pin(8) of IC702? Q307? pins(9) and (10) of IC702? No Yes

Yes Replace IC702. PC 8V line. Are 5V 2.3V voltage supplied to pins No Check line between the Q301, Q307 and

terminal motor? loading motor. Check the connection of optical pickup cable.

Yes If it is normal, replace the optical pickup.

Check for mechanism gear engagement and breakage.

FLOW CHART NO.20

FLOW CHART NO.17 Both picture and sound do not operate normally.
Set on the disc tray. No Does the optical pickup move up and down after See FLOW CHART NO.18<The [No Disc] indication. Yes check? Yes Replace IC302. Yes Is the level RF signal which is output from No Check for contamination objective lens of Yes pin(28) IC302, normal? optical pickup. FE output to pin(21) of IC302 when No Is there input signal on the pins(50,55) and (49,54) No Yes main PWB Replace the optical pickup unit. No

The [No Disc] indication. (In case of focus error)

is removed?(Checking of symptom.) (In case focus servo does not function.)> Is it possible to hold normally disc with Check the loading switch.

the disc is set? of IC302? Yes FE inputted into pin(8) IC401? Is there output signal on the pins(18) and (17) of IC301? Yes Yes No Check video unit and the audio amplifier unit.(Q209-Q211) or replace IC401. Check the connection of optical pickup cable. If it is normal, replace the optical pickup.

Yes No No

DV-720S/DV-720S(K) DV-720H

IC302 IC401. Check line between the IC301 and IC302.