The flavour text hints at Color Decoding, therefore we have to use its manual to solve this puzzle.
The TV says that we're in stage 1. We have 3 batteries, so we can assume that we have a checkered pattern. The 3 LEDs are yellow, purple and green, so following the rules of Color Decoding, we are using Set 2 and ignoring Sections A and C.
By taking the letter pairs from each row that you would press to solve a Colour Decoding module, we get the answer to the puzzle.
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