I'm sorry to hear that you're having trouble with your new TV and the remote codes.
Unfortunately, the remote codes are supplied by the service provider. If they don't have a remote code, and the search doesn't work, it may be because those codes aren't supported. If you have an older box, it might not have the remote codes. There are two suggestions in this case.
1. Work with your cable service provider to provide a newer box or one that might have codes for your TV. This may or may not work, depending on how robust their code bank selection is.
2. Try a Harmony Remote. Even the entry level 300 has codes for many of the new TVs and also has the ability to update as new devices come to market. I can't guarantee any device, but several people who have had similar troubles have reported success with that solution as well.
I have a 55" flat screen Samsung. I have been on the phone for a couple of hours with a Comcast tech and still can not get their remote to work with my TV. I have tried all the codes on their list and the procedure where you let the remote search for the code. No luck. Any assistance would be great. Just to ensure I am following the correct steps, I listed below what I am doing.\
Press TV button and release
Press SETUP button until TV button blinks twice
enter 991 and press the channel up button many many times.
TV never turns off. Help please.