Note: If SmartThings API was enabled by setting api_key and device_id, then these codes are also supported: ST_TV, ST_HDMI1, ST_HDMI2, ST_HDMI3, etc. which will change the input source faster then key chaining patterns will
Key codes can be chained with the "+" symbol, delays can also be set in milliseconds between the "+" symbols (default delay is 500ms), and if you wish to keep a key pressed you can set the desired time in milliseconds with the "," symbol.
This is a list of known and tested key chaining patterns. To see the complete list of known key codes, check this list
Switch to Live TV
KEY_EXIT+2000+KEY_TV+KEY_EXIT
Keep the volume up button pressed for 3 seconds
KEY_VOLUP,3000
Switch to first Source in List (2019 TV)
KEY_SOURCE+KEY_DOWN+KEY_UP+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_ENTER
Switch to second Source in List (2019 TV)
KEY_SOURCE+KEY_DOWN+KEY_UP+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_RIGHT+KEY_ENTER
Switch to third Source in List (2019 TV)
KEY_SOURCE+KEY_DOWN+KEY_UP+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_RIGHT+KEY_RIGHT+KEY_ENTER
Switch to forth Source in List (2019 TV)
KEY_SOURCE+KEY_DOWN+KEY_UP+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_RIGHT+KEY_RIGHT+KEY_RIGHT+KEY_ENTER
Switch to first Source in List (2017 TV)
KEY_SOURCE+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_ENTER
Switch to second Source in List (2017 TV)
KEY_SOURCE+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_RIGHT+KEY_ENTER
Switch to third Source in List (2017 TV)
KEY_SOURCE+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_RIGHT+KEY_RIGHT+KEY_ENTER
Switch to forth Source in List (2017 TV)
KEY_SOURCE+KEY_LEFT+KEY_LEFT+KEY_LEFT+KEY_RIGHT+KEY_RIGHT+KEY_RIGHT+KEY_ENTER