DX-V788W
Y The SHARP logo is not displayed.
Check C150.
Is the voltage on pin 52 (VREF) on IC14 (ES3883F) about 1.3 V ?
No
Yes
Is a 13.5 MHz clock signal available at pin 79 (PCLK) on IC14 ?Check the soldering on IC14 and the voltage at each pin.
No
Yes
Is the signal shown in waveform drawing 4, 5 and 6 beingCheck the soldering on IC15 (ES3880F) and IC16 and the
supplied to pin 82 (HSYNC), pin 84 (VSYNC) and pin 86 (YUV7)Novoltage at each pin.
on IC14 ?
Yes
Is a video signal available at pin 64 (VDAC) on IC14 ?Check the soldering at pin 64 on IC14, and Q12. If there is no
No
problem, IC14 is defective.
Yes
Check the CD Servo PWB connector and each transistor.
Y ERROR is displayed.
Is noise entering at the pickup mechanism ? Is the abnormalCNS2A/B and CNS3 are disconnected or broken.
No
operation so bad that the pickup moves to the outside of the disc ?
Yes
Is a 16.9344 MHz clock signal available at pin 79 (XO) on IC2X1 is defective, or IC2 is defective.
(TC9462F) ?No
Yes
Is pin 39 (PUINSW) on IC14 "L" ?Check the PUINSW (SW4) on the pickup mechanism and the
No
sled motor (M702). See whether pin 2 on CNS2A/B is broken.
Yes
Is a signal present at pins 2 ~ 8 on CNP805 ?Check IC14 and the peripheral parts.
No
Yes
The tray mechanism is defective.
Y NO Disc is displayed.
Does the pickup lens move up and down ?IC5 (LA6541D) is defective. CNS3 is broken.
No
The pickup (focus actuator) is defective.
Yes
Is the voltage at pin 12 (PD) on CNP303 about 180 mV during theCheck whether a voltage of about 1.9 V is being output from the
focus search ?NoQ1 collector during focus search. If not, Q1 or IC1 is defective.
If so, the pickup is defective.
Yes
Is an RF waveform of about 1.3V (PP) present at pin 22 (RFO) onIC1 is defective or CNS3 is broken.
NoThe pickup is defective.
IC1 ?
Yes
Can the eye pattern be observed ?IC2 or IC5 is defective.
No
Yes
The TOC data cannot be read due to flaws or dirt on the disc.
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ACEC
