THOMSON DTH175EL User manual

THOMSON DTH175EL Service Manual
THOMSON DTH175EL
Service Manual

THOMSON DTH175EL Service Manual
Table of Contents
General Section
Cautions/Warnings
Safe Warnings
Precautions
Software Upgrade
Exploded View
Circuit Diagram and Component Layout
MPEG IC Block Diagrams
Power supply Circuit Diagram and Component Layout
MPEG Circuit Diagram and Component Layout
Front panel Circuit Diagram and Component Layout
Servicing Procedures
Power Supply Trouble Service Flow Chart
Read Disc Trouble Service Flow Chart
Composite Video Trouble Service Flow Chart
Scart Video Trouble Service Flow Chart
S-Video Trouble Service Flow Chart
Composite Analogy Audio Trouble Service Flow Chart
Front Control Trouble Service Flow Chart
Remote Control Trouble Service Flow Chart
Parts List
Power parts list
MPEG parts list
Front panel parts list
AV Output parts list

THOMSON DTH175EL Service Manual
General Section
Cautions/Warnings
Product Safety Notice
Parts marked with the symbol in the schematic diagram have
critical characteristics.
Use ONLY replacement pares recommended by the manufacturer.
It is recommended that the unit be operated from a suitable DC
supply or batteries during initial check out procedures.
Leakage Current Check/Resistance Check
Before returning the unit to the customer, make sure you make
either (1) a leakage current check or (2) a line to insulated
resistance check.
If the leakage current exceeds 0.5 milliamps, or if the resistance
from chassis to either side of the power cord is less than 240 K
ohms, the unit is defective.
WARNING: DO NOT return the unit to the customer until the
problem or located and corrected.

THOMSON DTH175EL Service Manual
Safe Warnings
Protection of Eyes from Laser Beam
To protect eyes from invisible laser beam during servicing
DO NOT LOOK AT THE LASER BEAM
Laser Caution
CAUTION
Adjusting the knobs, switches, and controls, etc. or taking actions
not specified herein may result in a harmful emission of laser
beams. This CD Changer must be adjusted and repaired only by
qualified service personnel.
Laser symbol:
THIS IS COMPACT DISC PLAYER IS CLASSIFIED AS A CLASS 1 LASER
PRODUCT.
THE LASS 1 LASER PRODUCT LABEL IS LOCATED ON THE REAR EXTERIOR.

THOMSON DTH175EL Service Manual
Precautions
ESD Precautions in Repairing
1. Do not apply excessive pressure on the mechanical parts
(moving pares), including the Pickup Block, as extremely high
mechanical precision or required in these parts.
2. When soldering the microprocessor and signal processing IC’s,
use a ceramic soldering iron or a soldering iron whose metal part is
grounded since they are not resistant to static electricity.
3. When removing the solder or soldering the laser shorting lands
for the Pickup Block, use a ceramic soldering iron or a soldering
iron whose metal part is grounded since the laser diode or not
resistant to static electricity.
DVD Loading Unit Precautions when handling the Mechanism Block
1. Do not loosen any screws in the Pickup Block.
2. Do not adjust any screws in the Mechanism Block except for
“Tilt Adjust Screws”, as they are adjusted precisely at the factory.
3. Replacement of the Pickup Block is impossible. Always replace
the Traverse Ass’y when the Pickup Block needed to be replaced.
Do not touch the lens or lens holder of the Pickup Block.
4. The Guide Rails of the Pickup Block are greased. Take care
when handing.
5. When you try to slide the Pickup Block, do not press or pull it
directly. Always turn the dive gears with your fingers.
6. Be sure that the anti-slipping rubber on the turntable or clean. If
there is dust or it is greasy, clean the part with the liquid that
contains 50% each of alcohol and water.
7. When removing the Mechanism P.C.B. Ass’y, you need to
short-circuit the laser diode shorting lands beforehand.

THOMSON DTH175EL Service Manual
Software Upgrade
You can upgrade DVD Player using the software we provide as following step:
―Creating a software upgrade CD
―Use only a new CD-R/CD-RW(not an erased one).
―Give the CD a name of your choice(e.g. version and unit name).
―Burn the unpacked documents on the CD-R/CD-RW.
―The root directory(uppermost level) of the software upgrade CD
Attention: If a failure should occur during the software upgrade (e.g. a mains failure), it
may happen that the units function and a restart of the upgrade function are no longer
possible. If this should be the case, you must replace the intergraded FLASH ICs with
preprogrammed ICs (see corresponding spare parts list).
─Insert the upgrade CD (see corresponding spare parts list) and observe the hints on the
display and on the screen of the TV set.
─Carry out an initialization of the set.

THOMSON DTH175EL Service Manual
Exploded View

THOMSON DTH175EL Service Manual
Circuit Diagram and Component Layout
MPEG IC Block Diagrams
Fig. 2-1 MT1389

THOMSON DTH175EL Service Manual
Fig. 2-2 Functional block diagram
Fig.2-3 DVD Player system Diagram

THOMSON DTH175EL Service Manual
Table1. 1389C Pin Description