Introduction
One day I was cleaning  my electronics lab and during this I found a collection of old audio and video CD/DVD discs. At the age of my childhood these CD/DVD discs were most popular for listening music and watching movies. In modern world these CD/DVD discs have been replaced by semiconductor memory ( Micro SD Card, Pen Drive etc.). CD/DVD discs are also called as optical discs because these discs works on the basis of optoelectronic. I was not aware about the technology used in CDs/DVDs so I decided to learn about this technology. After a continuous study of 2-3 months I understood about this technology and I decided to make a DVD player. I have purchased the necessary hardware from online market. Like me if you have old CD/DVD discs and want to play them then this article can be really helpful for such people.

DVD Decoder Circuit (Board/PCB)
Thisboard is the mother board of a DVD player. It contains, CPU, ROM, RAM, Flash, DAC, DSP, Quartz Crystal, Audio and video processor chips. Sometimes these all chips are integrated inside a single chip only. My decoder board has a heatsink on the main IC so I do not know the number and manufacturer name. This decoder board is called MPEG decoder or DVD decoder or DVD card.

SMPS (Switch Mode Power Supply)
DVD decoder circuit works on DC power. The decoder board that i got requires +12V, -12V and 5V DC voltage levels to work properly. Instead of making a power supply circuit with multiple voltage outputs, I purchased a SMPS circuit that is specially designed for CD/DVD players. This power supply has following DC outputs

When I checked the output voltage of the SMPS circuit, I found that 3.3V terminal is shorted with 5V terminal but we do not need to care about it because our decoder circuit does not require 3.3V. 

DVD Mechanism
The Mechanisms of DVD players are made of poor quality plastic and acrylic, so please handle them carefully to prevent the damage of the mechanism. Wile working please keep this mechanism on a flat surface so during rotation  the edges of disc will not touch the body of mechanism. DVD mechanism contains three motor;

Mechanism also uses two switches one for detecting the position of optical lens and another for detecting the open and close of disc tray.
Disc Tray is a sliding tray it is controlled by some gears and loading motor. It takes the disc over the optical lens. During close process it pulls up the the optical lens close to the disc and during open it pushes the optical lens down. 

Pre Recorded CD/DVD
For testing our CD/DVD player we also need a CD or DVD disc with pre recorded music and video. Here in this project I am going to use a CD(Compact Disc). This CD/DVD player can play both CD and DVD discs. Both CD and DVD discs have same dimensions but DVD can store more data (Audio and Video). A typical CD disc can store 700MB of data and has a playback time of 74Min. while a typical DVD disc can store 4.7GB of data and has a playback time of  120-133Min. .

Wiring Connection Diagram
For making the wiring connections, I have purchased the JST connectors to avoid soldering process. This CD/DVD player require one 5-Pin and two 6-Pin JST connecting wires. I have also drawn a wiring connection diagram with wire names for beginners. With this diagram wiring connections are easy to understand. I have also shown USB wires but here I am not using them in my project. If you want to use USB drive that used can make wiring connections for it.

Start Wiring Connections

At the bottom of the DVD mechanism there the two small size PCBs. Both PCBs have JST sockets to connect the Spindle-motor, Sled-motor, Loading motor, tray-IN, Tray-OUT,  Home-SW to the decoder board. One PCB requires 5-Pin JST wire  and another PCB requires 6-Pin JST wire.

Connect the other ends of the JST wires to the decoder board as shown in the given image.

For connecting the display circuit to the decoder board I found that display board do not have JST connector so I connected the display board to the decoder board with ribbon wire and soldering tools. Here in the following image the names of the wires are listed.

Display PCB has six buttons on it. Name of each switch is following;

Optical pick-up system also known as optical lens moves under the disc so a FPC (Flexible printed circuit) ribbon is used to connect the optical lens to decoder circuit. Using a FPC as following advantages;
It is flexible so it can be folded easily.
It has light weight.
It
I am using SF-HD850 optical lens for reading the optical disc. It requires a 24-Pin FPC ribbon and it has a locking system to lock the FPC ribbon tightly. Before inserting the FPC end in the cavity of lock, pull the black part of of lock out as shown in the following image;

Insert the FPC end in the lock's mouth and push the black part of the lock to lock the FPC ribbon. During this process please have patience and keep your fingers smooth otherwise you will broke the FPC ribbon or lock.

Decoder board do not have the lock like optical lens for FPC ribbon. So observe the correct direction and smoothy insert the FPC ribbon in the mouth of FPC connector on the  decoder board. Please hold the FPC ribbon as shown in the following image.

For connecting the SMPS to the decoder circuit, insert the one end of 6-Pin JST connecter in the JST socket on the SMS board as shown in the following image;

Connect the other end of the SMPS JST wire to the decoder board as shown in the following image;

For connecting the SMPS circuit to the mains 220V/50Hz supply, I soldered a red and a brown wire to the SMPS circuit as shown in the image. You can also use main lead instead of wires. I do not have main lead so I am using wires here.

The decoder board has seven RCA female connectors for decoder output. Here each colour indicates a specific output type;