What voltage is your USB TTL adapter set to ?
If you short the Rx and Tx pins of the same, can you see your own typing in your terminal app ?
This could help too, Linksys E7350 Serial Port Problem or downgrade method - #19 by hecatae
What voltage is your USB TTL adapter set to ?
If you short the Rx and Tx pins of the same, can you see your own typing in your terminal app ?
This could help too, Linksys E7350 Serial Port Problem or downgrade method - #19 by hecatae