Fixing broken power supply? Answered
Have been using my FolgerTech Prusa i3 printer for a few weeks now, and was doing some cable management when, "Pop!" goes the power supply.
I had the mains power unplugged from the power supply, and didn't connect or disconnect any other wires. I was working on hiding some endstop cables (That i will probably just go ahead and shorten later) and when i was satisfied with the job, i went ahead and plugged the printer back in. Pop! Immediately unplugged the printer to prevent further harm. Sounded as if a .22 went off in my room. No burning or acidic smell, just a pop. From the sound of it, i assumed it had to be the power supply. So i examined everything, the ramps boards, the arduino, etc. Nothing. Everything looks fine. I remove the power supply from the printer, and plug it back in. LED light stays off, no more sounds. Using my multimeter, i checked the output voltage, and sure enough, it's dead.
So i go ahead and crack the power supply open, and begin examining the components.
All the caps look fine, no charred marks, no scorches or burns. No component looks any different than its functional counterpart. Beyond the cheap chinese soldering job, the board looks fine.
So i take the board off of the metal plate to examine the backside. Solder splatter everywhere, but no shorts or anything (It worked for about 3 weeks.). I do, however, notice that there is a nice dry joint on one of the large capacitors. Thinking that might be the problem, i go ahead and fix the joint by reflowing the solder. Put it back in its case, plug it in, nothing.
Anyone have any idea what may have happened?
I am a student who currently doesn't have 30$ to fork out for another power supply, but do have an arsenal of spare electronic components. (Will eventually buy another power supply, but currently don't have money to set aside for it.)
What should i look for? What blew up? Why does it not work anymore?
If any more info is needed, let me know!