Basic Troubleshooting Guide; Basic Troubleshooting Guide For Traverse Unit (Dvd Module P.c.b.) - Panasonic SA-HT540EE Service Manual

Table of Contents

21 Basic Troubleshooting Guide

21.1. Basic Troubleshooting Guide for Traverse Unit (DVD Module P.C.B.)

Problems

1) Distorted picture or abnormal

sound is heard during initialisation

2) No TOC/Long TOC

3) Disc not spinning

4) Traverse not moving

5) Traverse and spindle abnormal

movement

6) Cannot read disc but spindle is

spinning

- Cannot read CD

- Cannot read DVD

7) Block noise during play

Problems

8) Jitter out of specification

Checking Points

a) Check SDRAM address, data bus, CLK and

other control signals waveform

b) Check video signals

c) Check audio DAC circuitry

*Compare

*Compare the above with OK condition Module

the above with OK condition Module

a) Check motor driver circuitry (voltages)

b) Check laser drive circuitry (voltages and current)

c) Check LSI connection to motor drive circuitry

*Compare the above with OK condition Module

*Compare

the above with OK condition Module

a) Check connection from Backend Module to

Traverse unit

b) Check motor driver circuitry on voltages and control

signals

*Compare the above with OK condition Module

*Compare

the above with OK condition Module

a) Check laser drive circuitry (voltages and current)

- Check CD laser drive

- Check DVD laser drive

*Check

*Check voltages and LD current and compare with

voltages and LD current and compare with

OK Module

Module

a) Check SDRAM address and data bus signal

*Compare

*Compare the above with OK condition Module

the above with OK condition Module

Checking Points

a) Check LD current

b) Check OPU (change to other unit and confirm)

IC8051

LB8301, R8321, R8322, LB8302, R8325, R8326

IC8421

*Check