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

Filter 18.432M

Photocoupler

1. Haier plasma P32R1 TV. The issue is no sound and a black screen. The 5V power supply is normal, but the VS voltage is only 2.2V, while VA is 2.5V. It works normally for a while before the VS drops to 2.2V immediately after boot-up, indicating protection. After checking the power board, it was found that there's an adjustable potentiometer for VS voltage. Adjusting it to 183V resolved the issue.

2. Haier P32R1 occasionally has a black screen and shuts down during use. After testing at the service center, the machine didn’t fail. When returned home, the user’s voltage was 236V, while the service voltage was 218V. This suggests high voltage triggered protection. Upon retesting with a voltage regulator set to 242V, the machine wouldn’t start. Further inspection revealed two over-voltage protection circuits: one using a Zener diode (DZ1218.2V) and another with DZ12211V. At 236V, these were near breakdown. To function properly at 245V, both Zener diodes needed replacement. After adjusting their values, the machine worked without protection.

3. Haier P32R1 light not turning on, black screen. The 5V power supply is normal, and all voltages are okay when pressing the power button. Replacing the driver board resolved the issue. Another problem involved small black spots on the screen, which also disappeared after replacing the driver board.

4. Common Fault Analysis and Maintenance:

• No picture, standby light off: Check if the power switch is on and test the fuse and power board output voltage.
• Indicator light turns off after power-on, no image: Could be motherboard or Y-driver board issues. Test with a good motherboard or replace the Y-board.
• Blurred picture: Replace the Y-driver board.
• Image distortion: Check logic board connections and Z-drive parts of the power board.
• Vertical or horizontal lines: Inspect the logic adapter board and related cables.
• No image, flickering, or lines: Replace the module.

5. Module Functions and Fault Symptoms:

• Control Board: Controls signal output.
• Y/Z Drive: Receives and amplifies signals to drive the module.
• Y/Z FPC: Connects to the substrate for horizontal scanning.
• X Side: Processes data and outputs vertical signals.

6. Module Failure Causes:

• Drive Board: Color issues, no sound, no image, boot failure, interference, auto shutdown, screen shake.
• Logic Board: Abnormal screen output, boot failure.
• Power Board: No power to other boards.
• Z Drive: No image, color issues, flickering, boot failure.
• Y Drive: Boot failure, dark image.
• Sound Amplifier: No sound, speaker noise.
• Y/Z Drive Board: High temperature under load may indicate a fault.

7. Common Display Issues and Troubleshooting:

• No display: Check power connection, motherboard, module voltages, and LVDS cable.
• Non-working motherboard: Check soldering, power supplies, I2C signal, and crystal oscillator.
• No image: Ensure power supply and motherboard are working, check LVDS data transmission.
• No sound: Check power amplifier input, speaker connection, and U14 status.
• VGA issues: Check VGA socket and source device.
• VGA color or interference: Verify 5V power supply for D7, D9, D10.

8. Factory Debugging Mode:

To enter factory mode: Open menu, press 8893. Exit by pressing any key or OK. Use menu to navigate, program +/- to select items, volume +/- to modify settings.

• White Balance: Set based on signal source.
• Color Temperature: Adjust R, G, B values.
• Boot Logo: On/Off option.
• USB: Enable/disable USB switching.
• Power On State: Standby, Power On, or Last state.
• Subwoofer: Display or hide subwoofer settings.
• Signal Preset: Reset factory signal settings.
• E2PROM Reset: Reset memory after power cycle.
• Version: Cannot be changed.

The Haier P32R1 often experiences boot issues and 3A problems. In many cases, replacing the power board solves the issue. These repairs require careful diagnosis and component-level troubleshooting to ensure stable performance, especially in unstable voltage environments.