Basic Troubleshooting Guide For Traverse Unit - Panasonic SA-HT440P Service Manual

20.2. Basic Troubleshooting Guide for Traverse Unit

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 addresand data bus,
CLK and other control signals waveform
b) Check video signals
c) Check audio DAC circuitry
*Compare 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
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
a) Check laser drive circuitry (voltages and
current)
- Check CD laser drive
- Check DVD laser drive
*Check voltages and LD current and
compare with OK Module
a) Check SDRAM address and data bus
signal
*Compare the above with OK condition
Module
Checking Points
a) Check LD current
b) Check OPU (change to other unit and
confirm)
Checking components
IC8051
LB8301, R8321, R8322, LB8302, R8325, R8326
IC8421
*Check for solder short and/or component missing
/ damaged
IC8251
Q8550, Q8551, Q8552, Q8560, Q8561, Q8562
IC8001
*Check for solder short and/or component missing
/ damaged
FP8201
IC8251
*Check for solder short and/or component
damaged
Q8550, Q8551, Q8552, Q8560, Q8561, Q8562
Q8550, Q8560, Q8561, Q8562
Q8550, Q8551, Q8552, Q8560
*Check for solder short and/or component missing
/ damaged
IC8051
*Check for solder short and/or component
damaged
Checking components
89
SA-HT440P / SA-HT440PC