DOWNLOAD Panasonic SA-XH70GW / SA-XH70EE / SC-XH70EE Service Manual ↓ Size: 8.96 MB | Pages: 127 in PDF or view online for FREE

Model
SA-XH70GW SA-XH70EE SC-XH70EE
Pages
127
Size
8.96 MB
Type
PDF
Document
Service Manual
Brand
Device
Audio / DVD HOME THEATER SOUND SYSTEM
File
sa-xh70gw-sa-xh70ee-sc-xh70ee.pdf
Date
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41
10.2. DVD/CD Laser Diode current measurement
This section will illustrate proceddures of measuring & deriving DVD/CD Laser Diode Current.
DVD Laser Diode Current Measurement
CD Laser Diode Current Measurement
Checking Item/Formula
Remarks
Item Description
1. Measurement the voltage (V
CD
) on the testpoints CL8530(+) & CL8531(-).
This is voltage across R8566 which has a resistance value of 4.7 ohm.
2. Calculate the CD Laser current by the following formula:
CD_LD=VCD/4.7
1. Measurement the voltage (V
DVD
) on the testpoints CL8530(+) & CL8532(-).
This is voltage across R8556 which has a resistance value of 4.7 ohm.
2. Calculate the DVD Laser current by the following formula:
DVD_LD=VCD/4.7
Refer to 10.2.1. 
Backend P.C.B. 
(Fig. 3. Backend
P.C.B.)
Refer to 10.2.1. 
Backend P.C.B. 
(Fig. 3. Backend
P.C.B.)
3. Specification for CD laser current is
58 mA
3. Specification for DVD laser current is
58 mA
42
10.2.1.
Backend P.C.B.
Fig. 3. Backend P.C.B.
CL8530, CL8531, CL8532
R8556
R8566
(Side A of Backend P.C.B.) 
(Side B of Backend P.C.B.)
43
10.3. Basic Troubleshooting Guide for Traverse Unit (Backend P.C.B.)
Problems Checking 
Points
Checking 
components
b) Check video signals
i) IC8001 Pin 61, 63, 65, 66
ii) L4002, L4003, L4004, L4005
iii) JK4001
a) Check SDRAM address, data  
bus, CLK and other control signals  
waveform
IC8051
1) Distorted picture or
abnormal sound is head
during the initialization
b) Check laser drive circuitry 
(Voltages & current) 
Q8552, CL8532 (For DVD),  
Q8562, CL8530 (For CD)
a) Check motor driver circuitry 
(VCC PVCC)
IC8251 Pin 8, (+9V), 19 (+5V)
2) No TOC/Long TOC
c) Check LSI IC connection to 
motor drive circuitry 
IC8001 Pin 90, 93, 94, 95  
IC8251 Pin 11 to 18 
* Check for solder short and/or 
component missing/damaged 
a) Check connection from Main to 
Traverse unit 
FP8251
3) Disc not spinning 
4) Traverse not moving 
5) Traverse and spindle  
abnormal movement
b) Check motor driver circuitry on 
the voltages and control signals 
IC8251  
* Check for solder short and/or
 component damaged
6) Cannot read the disc but  
spindle motor is spinning 
- Cannot read CD/DVD
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 condition 
Main P.C.B.
Q8552, LB8551  
(For DVD Laser Drive current)  
Q8562, LB8561  
(For CD Laser Drive current)  
7) Block Noise during play 
a) Check SDRAM address and  
data bus signal
IC8051
8) Jitter out of specification
a) Check LD current
b) Check OPU 
(Change to other unit and 
confirmed operating condition)
OPU Unit (Traverse unit), FPC
connection (FP8531 & FP8251) 
44
10.4. Basic Troubleshooting Guide for HDMI AV output
Problems Checking 
Points
Checking 
components
1) Check setting of the set in  
Setup Menu whether the HDMI  
Video output is turned ON
* This year HDMI always ON. 
No need to check Setup Menu.  
If no resolution selection GUI,  
then only check SETUP. 
2) +5V Supply to the TV
IC3952 (Pin 4)
3) HDMI Connector Solderability 
condition
P3901
4) HDMI Output TDMS signal 
lines (IC3901)
- Clock (TXCP/TXCN => Pin 50, 49)
- Data (TXD0P/TXD0N => Pin 52, 51) 
- Data (TXD1P/TXD1N => Pin 54, 53)
- Data (TXD2P/TXD2N => Pin 56, 55)
 HDMI Connector (P3901)
- Clock (TXCP/TXCN => Pin 10, 12)
- Data (TXD0P/TXD0N => Pin 7, 9)
- Data (TXD1P/TXD1N => Pin 4, 6) 
- Data (TXD2P/TXD2N => Pin 1, 3)
- Data, DDCDAT (Pin 46, IC8001)
- Clock, DDCCLK (Pin 47, IC8001)
5) HDMI Transmitter communication 
lines to TV
6) HDMI Transmitter communication 
from DVD Decorder (IC8001) +3.3V
Supply
7) HDMI Transmitter DVD Decorder 
(IC8001) +1.8 V Supply
8) Hot-Plug Signal
9) HDMI Interface Reference
Resistor
1) Supply to HDMI transmitter 
intergrated (IC8001)
2) Check for Capacitor short to GND
Check Digital Signal Data 
communication lines from IC8001 to 
Serial Flash IC (IC8651)
Check the setting under 'SETUP'
menu if HDMI Audio Output option 
is turned 'ON'
- Clock (TXCP/TXCN => Pin 10, 12)
- Data (TXD0P/TXD0N => Pin 7, 9) 
- Data (TXD1P/TXD1N => Pin 4, 6) 
- Data (TXD2P/TXD2N => Pin 1, 3)
* Check for solder short/or 
component missing on TDMS line 
as well as signal intergrity HDMI  
Connector (P3901)
LB3905, R3905, Q3902, R3904 
LB3904, R3907, Q3903, R3906 
LB3901 (Pin 57)
LB3902, LB3910, R3910 (Pin 59)
LB3906, R3902, R3903, Q3901
C8034, C8006, C8029, C8028, 
LB3901 (Pin 57), LB3902, LB3910 
(Pin 59)
Pin 1, 2, 5, 6 (IC8651)
Pin 105, 106, 107, 109 (IC8001)
R3901
1) TV does not have any  
display. Set FL display shows  
U702/U703
2) When switching the video
output mode from 480p to 
720p /1080i, TV display 
become blank
3) Error Video Output. 
TV screen shows green
Display
4) No audio output from HDMI
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