The Main Menu for measurements and adjustments includes General Setting, Picture, Sound, and Debug options as detailed in Sections 8-2-1 to 8-2-5 of the manual.

Test high voltage only by measuring it with an appropriate high voltage meter or other voltage measuring device (DVM, FETVOM, etc) equipped with a suitable high voltage probe. Do not test high voltage by 'drawing an arc'.

A 'caution' message indicates that incorrect manipulation may damage the equipment, cause data loss, result in unexpected outcomes, or require restarting a procedure. Follow the instructions carefully to avoid these issues.

To exit the Service Mode, press the 'Exit' button on the remote control.

You can adjust the audio settings by modifying the values of the Audio Mode, which includes Treble and Bass.

The 'Burn In' function is one of the Misc settings available in the Haier LE50B7000TF TV. However, the manual does not provide specific details on its purpose. You may need to refer to additional documentation or contact customer support for more information.

To troubleshoot the power board, first check if CN4 Pin3/4 has a 5V input. If not, change the power board. If it does, check if CN4 Pin1 has a 12V input. If not, change the power board. If it does, verify if the DC/DC converters have the right output. If not, change the corresponding DC/DC converter. If all checks are correct, change the software. If the problem persists, change the mainboard.

First, verify if the same problem exists on other channels. If the issue persists only on the specific channel, check the picture and sound system of that channel. If the problem is still not resolved, change the channel to the correct sound system (PAL-BG SECAM/L) and refer to the relative instructions in the manual for color adjustment. If the issue continues, update the software and reboot the device, or consider changing the mainboard.

To troubleshoot a black and white display issue, first check if the problem occurs on other channels. If it does not, inspect the picture and sound system of the affected channel. If necessary, switch to the correct sound system (PAL-BG SECAM/L) and follow the color adjustment instructions in the manual. If the problem persists, try updating the software and rebooting the device. As a last resort, you may need to change the mainboard.

This issue could be due to a problem with the polarizer inside the panel. It might be caused by a scratch, a bubble, or a bladder between the polarizer and the top glass. It is recommended to check these components for any visible defects.