So, I've got this hartke 3500 (Yes ryan, same one, no I haven't gotten it fixed yet ). Turn it on, works nice sounds great. Set it on the cabinet (4x10) shuts off. Power is on, but no volume (You can hear the same click as when it turns on). Sometimes it just shuts off even when not on top of the amp. No idea what this is. I'm going to replace the tube, but I don't think that's the problem. Any ideas guys and gals?