Just in case you aren’t aware of, your ATA PTX-5 TrioCode garage door remote has a easy-to-use feature called Remote Learning, which is particularly useful if you didn’t have access to receiver box.
In general, remote learning feature on garage door remotes is usually activated by a already programmed remote, and allows new remotes to be programmed without pressing any button on receiver board.
Every model has a different activation button or so called hidden button to use this feature, some garage remotes use a coding hole, while others use combination key.
On genuine ATA PTX-5 remote, remote learning is activated by press the coding hole using needle for more than 3 seconds.
While in our replacement ATA PTX-5 remote, remote learning is activated by press button 3 and 4 together at the same time for more than 1 second.
Also we made a short video explains programming ATA PTX-5 aftermarket remote, which can be found here http://www.youtube.com/watch?v=To59ctFZyLQ