Haier plasma TV P32R1 black screen troubleshooting method - android - Phones Developers

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1. Haier plasma P32R1 TV. The issue is that the TV has no sound and a black screen. The 5V power supply is normal, but the VS voltage is only 2.2V instead of the expected 190V. Similarly, VA is at 2.5V instead of 60V. However, during normal operation, it works fine for a while before the voltage drops. At startup, the VS voltage is 190V, but quickly drops to 2.2V, suggesting a protective shutdown. After checking the power board, there was an adjustable potentiometer for VS voltage. Adjusting it to 183V resolved the issue temporarily. 2. Haier P32R1 occasionally experiences a black screen and flashes. The user reported that the TV sometimes shuts down while watching. Due to the intermittent nature, the unit was returned to the service center, but it didn’t fail during testing. After returning it to the user’s home, the TV failed again. The user's voltage was 236V, while the maintenance voltage was 218V. It was suspected that high voltage caused the protection. After adjusting the pressure regulator to 242V, the TV wouldn’t turn on. Further inspection revealed two over-voltage protection circuits on the main power board. One used a Zener diode (DZ1218.2V), and the other used DZ12211V. When the input voltage reached 236V, these diodes were near breakdown. To operate at 245V, the Zener diodes needed replacement. After changing them, the TV functioned without triggering the protection circuit. 3. Haier P32R1 does not turn on, resulting in a black screen. The 5V power supply is normal, and all voltages are correct after pressing the power button. Replacing the driver board helped resolve the issue. Additionally, some images had small black spots, which were also fixed by replacing the driver board. 4. Common Fault Analysis and Maintenance Measures: - No image and no red standby light: Check if the power switch is on and test the fuse and power board. - Red light turns off after power-on but no image: Check the motherboard or Y driver board. - Blurred image: Replace the Y driver board. - Image distortion (top/bottom/left/right): Check the logic board and Z drive connections. - Vertical or horizontal black lines: Inspect the logic adapter board and module cables. - No image with flickering or single lines: Replace the module. 5. Function of Each Module and Fault Symptoms: - Control board: Controls output signals. - Y/Z Drive: Receives and amplifies signals to drive the module. - Y/Z FPC: Connects to the substrate for horizontal scanning. - X Side: Processes image data and outputs vertical signals. 6. Various Fault Phenomena Caused by Module Failure: - Movement Board: Color issues, no sound, no picture, boot failure, interference, auto-shutdown, screen shaking. - Logic Board: Abnormal screen output, boot failure. - Power Board: No image, no power to other boards. - Z Drive: No image, poor color, flickering, boot failure. - Y Drive: Boot failure, dark picture. - Sound Amplifier: No sound, speaker noise. - Y/Z Drive Board: High temperature may indicate a fault. - Z Drive and Cables: Issues with signal transmission. 7. Common Movement Failure Analysis: - Screen not lit: Check power connection, motherboard, VS/VA voltages, LVDS cable, and standby 5V. - Motherboard not working: Check soldering, power supplies, I2C signals, and crystal oscillator. - No image: Check power, motherboard, and LVDS data. - No sound: Check power amplifier, speaker, and U14. - No VGA image: Check VGA socket and source. - VGA color issues: Check 5V power and signal lines. 8. Factory Debugging Methods: - Enter factory mode by opening the menu and pressing 8893. - Exit using the OK button. - Use the menu key to navigate, program +/- to select items, and volume +/- to adjust values. Instructions: - White balance settings: Choose signal source and automatic white balance. - Color temperature: Set to cool, standard, or warm. - Boot Logo: Enable or disable the logo. - USB: Enable or disable USB switching. - Power On State: Choose between standby, on, or last state. - Subwoofer: Display or hide subwoofer options. - Signal Preset: Run factory signal preset. - E2PROM Reset: Reset memory after AC power loss. - Version: View firmware version. Haier P32R1 and similar TVs often experience issues like 3A problems or boot failures, typically requiring power board replacement.