Haier 21F07 Service Manual

Before attempting to diagnose and service the Haier 21F07 television, you should carefully read the manual to ensure you can correctly identify and troubleshoot any issues.

Replacement parts must be identical to those used in the original circuits. Service should be performed by qualified personnel only. Replacement parts which have special safety characteristics are identified in the parts list of the Service manual. The use of a substitute replacement which does not have the same safety characteristics as the recommended replacement part may cause shock, fire, or other hazards.

The 'AGC Take-over point' is a setting that controls the Automatic Gain Control (AGC) take-over point. You can adjust it using the direct access key '4' and selecting the item 'TOP'. The preset value for this setting is 20, and it is adjustable.

To enable the Arabic language setting, you need to set the ARABIC_SET bit to 1. This can be done by accessing the OP2 settings and enabling the corresponding bit.

To adjust the purity of the screen, follow these steps: 1. Demagnetize the CRT with the demagnetizer. 2. Loosen the retainer screw of the deflection yoke. 3. Remove the wedges. 4. Input a green raster signal from the signal generator and turn the screen to green raster. 5. Move the deflection yoke backward. 6. Bring the long lug of the purity magnets on the short lug and position them horizontally. 7. Adjust the gap between two lugs so that the GREEN RASTER will come into the center of the screen. 8. Move the deflection yoke forward, and fix the position of the deflection yoke so that the whole screen will become green. 9. Insert the wedge to the top side of the deflection yoke so that it will not move. 10. Input a crosshatch signal. 11. Verify that the screen is horizontal. 12. Input red and blue raster signals, and make sure that purity is properly adjusted.

If the screen is not displaying a green raster properly, ensure that the deflection yoke is properly positioned and that the purity magnets are correctly aligned. Move the deflection yoke backward and forward as needed, and adjust the gap between the long and short lugs of the purity magnets until the green raster is centered on the screen. If the issue persists, verify that the signal generator is correctly inputting the green raster signal.

To perform a static convergence adjustment, input a crosshatch signal. Use the 4-pole convergence magnets to overlap the red and blue lines in the center of the screen and turn them to magenta. Then, use the 6-pole convergence magnets to overlap the magenta (red/blue) and green lines in the center of the screen and turn them to white. Repeat these steps to achieve the best convergence.

For dynamic convergence adjustment, move the deflection yoke up and down to overlap the lines in the periphery. Then, move the deflection yoke left to right to overlap the lines in the periphery. Repeat these steps to achieve the best convergence. After adjustment, fix the wedge at the original position, fasten the retainer screw of the deflection yoke, and fix the 6 magnets with glue.

To adjust the main voltage, you can use the adjustable resistor R817A. This resistor allows you to select between 150V, 220V, and 330V.

The STAND BY function is used to put the TV in a low-power state. This function is controlled by specific components and resistors, such as R214 and V206, which help manage the standby mode.