If the first code fails, try the next one on the list. Manufacturers often have dozens of codes for a single brand because different models use different internal chips. Using the "Auto-Search" Method
If you have a popular remote brand (RCA, GE, Philips, etc.), you can usually find the specific manual PDF by searching the model number found in the battery compartment.
The moment your TV turns off, press or Save to lock in that signal.
This connection relies on a numeric "address"—the programming code. Below is a curated master list of the most common codes for major brands, followed by the professional secrets to programming them.