Thank you for the information. If the TX led light didn’t flash, then for some reason the TX module has been turned off.
Can you check if the TX led flashes four times after power up? If not, please go with the following steps.
1, Make sure the MUTE button didn’t been pushed.
2,Make sure the transmission has been enabled through configuration tool(you need connect A051 to a computer via USB port, and see ‘connected’ on the bottom of the configuration tool before checking the settings).
Keep us updated please.