If you are a subscriber of cable television, you will need to carefully read the user manual where everything is written in detail and follow the prompts to configure the channel TNT either in automatic or in manual mode. But if these options have not worked then the reason may lie in the receiver, so it is better to call in dispatching service. There will either explain to you what to do, or send the masters to your home to deal with the problem.
The same thing you should do, if earlier, TNT was showing perfectly, and then the reception quality is suddenly deteriorated. The Manager needs to be sure to check the cable and passing the signal to the subscriber.
If you have individual antenna, but receives weak signal TNT low quality, then it's most likely because of the large distance between your antenna and the Central tower, or because of various interferences on the signal path.
Try in this case to change the installation point of the antenna and its direction. When you want to change the position of the antenna may begin to not accept a direct signal and the reflected, which will be the best quality, and of TNT you will have a great show.
If you have satellite TV, then have a look at the basic settings. Perhaps disabling the channel or the deterioration of the reception due to the fact that lost the basic settings of the host plate.
Compare performance with the standard that look like this: menu "Setup" (enter the code 0000) -> LNB: the name of your partner, lower frequency, upper frequency. Compare these settings for the missing channel and one of the workers. Write down what they disagree, and then put it on TNT the same settings as on the working channel.
Perhaps the channel stopped showing in connection with the update. Then you just need to wait until the new software installation will end and you will again be able to enjoy their favorite channel.