The production process for a P4 indoor full-color LED screen includes material preparation, assembly steps, and precautions, as detailed below:
I. Material and Tool Preparation
Outer Frame: Special aluminum profiles, corner pieces, light steel keel, back panel (aluminum composite panel or OSB).
Display: Unit boards, ribbon cables, power cords.
Control: Control cards, adapter boards (some control cards do not require this), ribbon cables.
Power Supply: 220V-5V power supply (commonly 40A or 30A, select according to startup requirements).
Small Accessories: 16P ribbon cables, 16P connectors and clips, three-core data cables, DB9 connectors (pins/holes), DB9 housings, power cords, self-tapping screws, strong magnets (for support posts and magnetic sheets).
Tools: Cutting machine, wire crimping pliers, soldering iron, wire strippers, screwdriver.
II. Assembly Steps
Confirm Outer Frame Dimensions: Accurately measure the dimensions of the P4 unit boards (millimeter-level precision) and calculate the net dimensions (height × width) of the unit boards inside the display screen.
Assemble the Outer Frame: Connect the corners to the cut aluminum profile using self-tapping screws. After cleaning away debris, place the boards face down.
Install Unit Boards: Arrange the unit boards according to their orientation (pins facing the highest point of the profile). Fix the magnetic support posts to the unit boards, embedding the magnetic pieces into the grooves of the support posts.
Cut a piece of light steel keel and place it in the center of the magnetic keel. Secure the keel to the frame using self-tapping screws.
Connect Unit Boards: Bridge the unit boards with ribbon cables, avoiding cable twisting.
Secure the Power Supply: Fix the power supply in a suitable position inside the profile (usually below the display screen), ensuring insulation from the unit boards.
Power Cable Connection Rules: The display screen wiring is in parallel (positive to positive, negative to negative, e.g., VCC/+5V/+V is positive, GND/COM/-V is negative). A single P10 unit board draws 4A at full current. A 40A power supply can power a maximum of 10 unit boards; it is recommended to connect them in separate circuits (≤4 boards per circuit).
Control Card Installation: Place the control card at the unit board input terminal and draw 5V power directly from the power supply.
Connect the pins to the top position of the unit board input terminal in the correct order (e.g., JK1, J1, etc.).
Control Card to Unit Board Connection: Match the white letter "A" next to the control card pins with the same character on the unit board input terminal, and connect them in parallel using a ribbon cable.
Cleaning and Testing: Clean any debris from inside the screen (avoid conductive aluminum dust, iron filings, or wire ends that could damage the circuit board).
Power-on Test (if abnormal symbols or bright spots are displayed, confirm that the positive and negative terminals are correct).
III. Data Cable Soldering and Adjustment
Data Cable Soldering:
Extension Cable: Connect the DB9 pins and holes using a three-core cable, solder pins 2, 3, and 5, and attach the housing to the pin ends.
Crossover and Straight-through Cables: Select according to the control card type. For crossover cables, swap pins 2 and 3. Adjustment and Testing: After powering on, adjust the display screen (adjustment method for the control card varies depending on the model).
Continuously test for 2-5 days. After confirming there are no problems, seal the back cover and deliver the product.
IV. Precautions
Voltage Limitation: The power supply to the unit board and control card must not exceed 5V.
Positioning Correctness: All lines must be connected correctly (positive and negative terminals must be correct), otherwise the unit board will be unusable.
Cleaning Requirements: The inside of the screen must be free of conductive debris.
AC Power Characteristics: 220V AC power has no polarity.
