The lnb is standard 12.2-12.7 circular.
The beam patterns for all transponders are identical.
I would check for signal existence on all the transponders using your circular lnb.
If they are all there, the Dish (USA) transmissions are also there.
It might be that you have not activated a Dish account on your box. You probably can not activate using the 77W signal. But, after activation with access to one of the other Dish satellites (77 probably does not carry the activation stream), it should work.
That's my best guess
The beam patterns for all transponders are identical.
I would check for signal existence on all the transponders using your circular lnb.
If they are all there, the Dish (USA) transmissions are also there.
It might be that you have not activated a Dish account on your box. You probably can not activate using the 77W signal. But, after activation with access to one of the other Dish satellites (77 probably does not carry the activation stream), it should work.
That's my best guess