MY REGULATED POWER SUPPLY DIED

Hi everyone yesterday my Smart 2 regulated power supply stopped putting out 13.8 v at the front opened it up and put a voltage tester around, all the fuses are good, it has mains ower coming in fine , goes into transformer , comes out with 1 x 17.5 volts dc & 2 X 34.9 volts that goes to simple circuit board with 1 single large capacitor and and diodes and adjuster pot etc. And wired to a 2n3055 transistor from info from Google and YouTube videos I'm guessing that it's the 2n3055 transistor that is at fault I'm not really knowledgeable in electronics the power regulator was running on very hot day in sun for long period and just stopped working I was hoping one of you guys may have a better idea thanks for any info

Without being able to put a multimeter on it,test diodes and see if there's an input voltage to the regulator its not really possible to give a definitive "yeah its that" answer.

Seconded... someone needs to work through it with a meter and check out the transistors. You could start by unsoldering the base and emitter of the 3055 and check it with the diode check range of a meter looking for a normal 0.7V ish drop from base to emitter and collector and infinite resistance between collector (case) and the pins (one way around).

Trouble is, its all going to be DC coupled so even if the 3055 is dead that may have been caused by whichever transistor drives it going short and killing it so really you need to work your way back through the chain. Check that old preset voltage adjust resistor too to make sure the wiper still connects.

A dead or dried up electrolytic capacitor is possible too but would have been unlikely to stop the output altogether.... if you find the fault it might be a good idea to change out the main smoothing capacitor anyway while you are in there.

Lastly, there might be a zener diode in there if the preset is only a fine voltage adjust, might be worth checking that too.

Thanks guys for your reply, I've took out 2n3055 seems ok so now decided to wait for a professional who knows what they are doing to sort it out before messing it up further cheers any ways good luck happy radioing and 73's

sometimes you may find a linear voltage regulator transistor like what was fitted in the old Bremi power supply's of the day this can also be the route of the problem. but I agree working through the board is the only sure way to find the culprit that's causing the problem bit by bit with a soldering iorn and a bit of patience and a meter ohh and don't forget a few cups of tea