A little off subject sub

[doveguy1]

Hi,

On the back of my receiver is an RCA output for the sub.
Is there any way I measure if it is working with a multi matter,

Sub amp is powering up the green light. Tested Sub driver working, No output on the sub amp.

Not sure if the amp is bad or not getting signal.

Any ideas

 

[doveguy1]

Also when plugging the cable into the sub amp there is no hum when only partly plugged in

 

[rayma]

Also when plugging the cable into the sub amp there is no hum when only partly plugged in

That would tend to be the sub as the problem.

 

[MAAC0]

Connect the sub to the main outs with volume down or tape outs and verify if the sub plays.