Power Supply Repair walk & talk, multiple faults, SkyTronic 13.8v DC 27amp

Here we have a SkyTronic power supply reporting a very high voltage output & unregulated, we find signs this has been worked on by somone else prior, Before dareing to plug in we internally inspect only to find a resistor taped to the top of the transformer by the last repairer, whihc looks to be burned out but that isnt the case as electrically its fine its just got hot thats all, we also progress in working out how the supply works & draw this, we work out using ohms law, & mathermatics the current, wattage, & voltages in an example circuit. we also back work the maths to check the results. We find the main voltage regulator voltage reference a 3.3v Zenner is defective. we then replace the Zenner & the 220 ohm resistor with a new one. At this point & from experiance i know to check the series pass 2N3055 X5 as its comon for one of more transistors to fail, we check each transistor individually measuring the transistor NPN junctions Base, Collector, Emiter only to find one of the transistors has gone Collector Emitter short. we also find the transistor has a second fault between Collector & base too. so one transistor has two countable faults. we replace the transistor & also have to apply silicone heatsink compound to all transistors as none had any applied to the mica insulating washers, we then put the unit back together & test the output voltage & its regulation under a test load of 16 Amps.