Greetings all! I recently inherited a broken Pioneer sx-780. I feel pretty confident that the Darlington power packs are fried. -- Back story: Several years ago the previous owner built some custom speakers and had a short on both speakers when the unit was powered on, ever since the unit's protection relay would not click on. He had it diagnosed and was told the "output transformer" was blown. I suspect he meant output transceiver which should indicate the power packs. -- I opened up the unit today and both 1a fuses @ FU3 and FU2 were blown. I replaced them and they immediately blew again upon powering on. I've removed the power packs and powered on the unit with only a fuse in FU3. The protection relay will now click on and it appears the tuner works because the tuning needle will move and the source light is now active. Should the headphone jack work with the darlington's removed? I figured it would but it does not. I'm not sure where to go from here, i'm afraid to install a new set of packs and potentially fry them also. I have a basic multimeter but the fuse is bad so i dont have any readings at the moment and i'm not sure what / where to measure. I'm not that great with electronics and the schematic i'm staring at might as well be in another language. Any help would be greatly appreciated! Thanks!!