how to test whether my onkyo 705 is broken or whether its the subwoofer

My subwoofer has stopped working its the Aego t set up.

I am trying to acertain whether its the subs fault or the onkyo's fault.

is there a way i can plug a sub into a different connection on the 705 to check to see whether any sound can be played through the sub.

ie i am trying to find out whether the standard subwoofer socket on the onkyo is defective hence why no sound is being heard from the onkyo or whether the sub has failed.

i dont want to go plugging into the wrong hole on the amp and blow the thing up for example.

would there be a safe alternative connection on the onkyo i could use to send sound to the subwoofer and hence check it.

thanks in advance

 

anyone?