Shorted Power In, fuse not blown, No Power
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So my Geetech A10M had a stepper driver that died. I have a spare Duet Wifi laying around with an external fuse bypassing the resettable 5V fuse from the step down 5V supply on the board. The reason I mention this is listed below later.
The A10M used a 16pin connector for its gantry harness and I wanted to reuse it, so I pinned out this connector but made a small mistake which now typing it sounds very dumb, butttt its all said and done now. I just want to see if the board is easily repairable.
So upon wiring up this jumper for the gantry connector I wired some 24V pinouts labelled on the original A10m controller to the Power IN on the board (just the + side) and now with everything disconnected, and a bench supply set to 24V, it shows the voltage drops to 1.5V. Clearly I shorted something over but I am not sure where to look.
USB function and 5V power works just fine. With USB power the board operates as normal.
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Sounds like a regulator is blown.
With vin connected does anything get hot to the touch?
Can you see any visible signs of damage on any of the smaller chips?
Photos? -
I don't see any physical signs of burnt out components and that's why I am a bit stumped, but I am no expert. No smoke came of it either. The PSU just gets loaded down, then it I shut it off immediately.
Edit: just tested it again today and it now only has the VIN led light up, no 5V or 3.3V. So definitely the Regulator. I looked up the schematic and found the buck converter to 5V (I think) on U3.
I assume this is what is blown? There is a small bubble in the plastic on the corner, its not the orientation dot. There is also a small piece of bluing ink missing over a trace. Not sure what that means. I haven't tried to tamper with that yet.
See photos below. (Also please ignore my fuse bypass, it works, just doesn't look the best)
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Yes it's likely U3 that has failed.
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@phaedrux great, thank you. Now to fine one that is in stock. Seems to be bigger challenge than I'd expect.
