Using ZL-680 decompression board to convert into a CD player

I recently used the ZL-680 decompression board to convert a Baojia 2213CD player into a VCD player. It was successful at the first try without any other tinkering. The picture, sound and color are excellent, and the screen is extremely clean without any mosaic. I would like to share my experience as follows:

1. Power supply connection

The ZL-680 decompression board comes with a rectifier, filter, and voltage regulator circuit. The chip power supply is +5V, and the voltage regulator circuit is a 7805 with a heat sink installed. Therefore, the power supply connection is very simple. If the modification is not an LD player, but a CD player, the power supply only needs to add a single 9V AC transformer of loW, and the two secondary wires of the newly added transformer are connected to the J7 power supply input terminal of the decompression board. Because the power filter capacitor on the decompression board has a too small capacity (1000μF), it is necessary to add a 2200μF/16V capacitor and connect it to both ends of the original 1000pF capacitor, and fix the capacitor to the bottom plate with silicone grease.

2. Three signal line interface

The modified Baojia 2213 is a low-end machine. Its chip SDP model is CXD1167. The signal output pins are: pin 76 is the BCLK word clock line pin, pin 78 is the DATA data line pin, pin 80 is the LRCK bit clock line pin, and pin 57 is the +5V power supply pin. Before modification, pin 57 should be removed from the original circuit board and connected to the positive 5V power supply terminal of the CD board with a 500Ω resistor in series. The ZL-680 decompression board still uses the three-wire wiring method. Its socket is a five-wire shielded plug. The socket is numbered J1. The method of connecting with the 1167 chip is as follows. The procedure is to count from right to left. J1-1 is an additional control line, which is temporarily unused. J1-2 is the signal ground line. In order to prevent damage to the chip, the three signals are wound around to the KDA0316 integrated block and grounded nearby. J1-3 is the BCLK word clock line pin, connected to pin 76 of the 1167 chip, J1-4 is the DA-TA data line pin, connected to pin 78 of the 1167 chip, and J1-5 is the LRCK bit clock line pin pair, connected to pin 80 of the 1167 chip. These three signal lines are soldered from pins 76, 78, and 80 of the 1167 chip along the printed board to the corresponding pins of the KDA0316 integrated block.

3. Audio and video signal output

The audio signal of the ZL-680 decompression board is a three-wire socket, numbered J5, and the video signal output socket is a two-wire socket, numbered J4, both of which are wired plugs. When modifying, if the original left and right channel sockets are reserved for CD playback, then three 10m holes must be drilled in the rear case (pay attention to the original hole spacing specifications when drilling), respectively for audio and video output. Lotus sockets are available in the market, with two-in-one and four-in-one sockets. Use scissors to cut it into two-in-one sockets, fix it firmly with screws or silicone grease, and connect the audio frequency line.

4. After the above wiring inspection is correct, power on the machine for testing

After installing the disc, the 5V voltage of the decompression board is normal, and the voltage output of the three signal lines of BCLK, DATA, and RLCK is normal. The display screen has a song display, and the full-color Sony logo, menu, and image have appeared on the TV screen. The picture, sound, and color are very bright and pleasant. After replacing a disc of Ai Kadai, it is as smooth as flowing water, sweeping away the more or less pauses, squares, shifts, and other headaches after using the 480 type to modify the machine for two years. Its error correction ability is far beyond the general finished machine.

5. Selection and Trade-off of Additional Functions

ZL-480 decompression board has expanded many new functions based on CL480 (please refer to the instructions for use later). If the customer has no more requirements, and considering the appearance of the panel and the malfunction caused by improper operation of the user, some special functions are also troublesome, so it is better not to use general auxiliary functions. Only a sing-along function is added, a 3mm small hole is punched on the back panel, and a micro switch used in TV is installed on it, fixed with silicone, and two wires are welded from the decompression board numbered J12 to the two pins of the micro switch.