Press the INPUT button on the remote to select the correct input source.
Check that the device is turned on and functioning correctly.
Check if the power cord is plugged in and the TV is turned on (front red LED light should be on; not blinking)
Press the INPUT button on the remote to select the correct input source.
Ensure all connections are correct and secure.
When using external video source, such as a Cable/Satellite box or DVD player, check that the device is on and functioning correctly. 
Press MENU on the TV’s remote control. If the menu is displayed, then the TV is working; recheck above steps.
Press the INFO button on the remote to confirm the type of signal being received (p. 17). HD signal should be 720P, 1080i or 1080p.
Select a High Definition channel from your HD source (Cable, Satellite or fiber optic service). HD channels sometimes broadcast 
Ensure that your HD source (HD box, 
Change the format (aspect ratio) of the picture by pressing the FORMAT button on the remote control. (p.18)
Check the aspect settings on your external video source, such as Cable/Satellite box, 
When using a cable service (without a box), check that all connections are secure.
When using a cable or satellite box, change the connection (wiring) to Composite, Component or HDMI. (p.10)
If you’re using an antenna, then check that connections are secure. Change the position or direction of the antenna and check the “Signal meter”. (p.43)
Check if electrical products such as kitchen appliances, fluorescent lights or light dimmers are nearby. They may interfere with the TV’s picture.
Try viewing a picture from another device, such as a DVD player or a game console, to narrow down the source of the problem.
Change settings of Closed Caption (CC). (p. 17, 53)
The TV has gone into shutdown mode to protect itself. Try unplugging it for a few minutes and connecting it again. If there was a temporary power surge on the AC line it may now be OK. If the blinking returns, call 
The LCD panel is made up of a few million pixels and is produced with advanced technology through an intricate process. Sometimes a few pixels may be bright or dark.
TC-L42D30 specifications
The Panasonic TC-L42D30 is a notable flat-panel television that captures the attention of viewers with its impressive features and performance. As part of Panasonic’s D30 series, this LED LCD TV is designed to deliver an outstanding viewing experience with a focus on clarity, color accuracy, and connectivity.At the heart of the TC-L42D30 is its 42-inch display, which boasts a full HD resolution of 1920 x 1080 pixels. This high-definition capability ensures that images are vibrant and detailed, making it ideal for watching movies, sports, or playing video games. The television features an IPS panel, which provides wide viewing angles, allowing multiple viewers to enjoy the picture quality without significant color distortion or loss of brightness.
One of the standout technologies integrated into the TC-L42D30 is Panasonic’s VIERA Technology. This advanced technology enhances images through better color reproduction and contrast ratios, resulting in a more lifelike viewing experience. Additionally, the TV is equipped with a high-speed 120Hz refresh rate, which minimizes motion blur during fast-paced scenes, making it suitable for action-packed films and sports broadcasts.
Sound quality is also a crucial aspect of the TC-L42D30, and Panasonic has not overlooked this feature. The television is integrated with a 20-watt audio system that includes Dolby Digital decoding, providing clear and immersive sound. This enhances the overall viewing experience, ensuring that viewers not only see sharp pictures but also hear every detail.
For connectivity, the TC-L42D30 comes with multiple HDMI ports, USB ports, and composite inputs. This extensive connectivity allows users to easily connect various devices such as gaming consoles, Blu-ray players, and streaming devices, making it a versatile choice for modern entertainment setups. Moreover, the TV features VIERA Connect, which enables users to access a range of streaming services and apps directly from the television.
Furthermore, the TC-L42D30 includes energy-saving features that help reduce power consumption, making it an eco-friendly option. Its sleek design and slim profile also allow it to fit stylishly into any living space.
Overall, the Panasonic TC-L42D30 is a well-rounded television that combines advanced display technologies, high-quality audio performance, and extensive connectivity options. Whether you're a movie aficionado, a sports fan, or just looking for a reliable television for daily viewing, the TC-L42D30 delivers an impressive and enjoyable experience.