Converter box codes are located within the box's code search program. To access converter box codes, switch on the television and the converter box, choose the program button, wait for the remote to send the code and get a response from the TV with a list of codes.
Some universal remote controls have code search buttons that navigate through the lists of common codes for the installed converter boxes. For converter boxes without functional remotes, switch on the television, and hold the power button to get it into programming mode. Use the Up and Down arrow buttons to scan through the list of codes.