I recently took my AVT150H out after not playing it for a few years. I turned it on and it powers up normally but there is no sound coming from my AVT412A cabinet. I checked all the jacks and there is proper contact and no corrosion or broken solders. The cabinet jack is properly connected and functional. (It has been stored in a dry location.) All the channels are operational and able to be controlled by the foot switch. However when I plug a set of headphones into the headphone jack I can hear the guitar playing perfectly, so the amp is operational. Where should I go from here?