Forgive me for asking about repair info on a non marshall but I figured It would get more eyes here than anywhere else. I just received a used mesa heartbreaker head from GC...I know, I know but I've gotten tons of used gear in the past from them and never had a problem.That is until now. The amp came in good condition box wasn't torn up,tubes came bubble wrapped in a separate box and labeled. Don't know how much life is in the mesa branded tubes but they fired up and looked ok. Problem is that when turning it on there varies from no sound, very little sound to full power intermittently.Also since the sound cuts in and out I can't tell much if the various swtches and knobs work.It's a fairly rare amp and has 60/100 power,variac switch,tube/solid state rectified, reverb,2 channels, 5 modes etc. It's kind of an a 25 anniversary to the mk 1 but does fender tweed, bassman, deluxe,twin on steroids jtm plexi . The amp ticks all the boxes and I got a pretty good price but not if I have to sink a bunch into it.I've got a good tech that's an hour and a half away so I'd have to drop it off. Question is do I return it and possibly miss out on a great amp or bring it in?