Only one speaker outputting sound on my XXX 2x12

[MegaMustaine]

Hey guys-

 

I'm selling my XXX head to someone tomorrow (hopefully) but he obviously wants to test it out. I'm noticing that when I hook up my head to the 2x12 cab, I'm only getting sound out of one of the speakers.

 

Honestly, I've had this amp since when I was a bit of novice, I'm sort of thinking it's been doing this the entire time I've had the amp and I haven't known.

 

On my XXX 2x12, theres a mono and stereo switch, and two inputs (left and right).

 

I have mono selected, and am running the head at 16 ohms (what the cab says). But i'm not getting ANY sounds out of the left side speaker on the cab.

 

I opened the back up and checked the wiring, and it all looks good to me. Is it possible for a speaker to just go completely bad? or is something wrong with my configuration.

 

Again, I'm using one speaker output and going from the output of the XXX to one of the two jacks on the cab, and the cab is set to mono. Head set to 16 Ohms.

 

After further research, I'm starting to think I have a bad speaker that I've had all this time. Speakers aren't great in the XXX anyway, but still. Argh!