Damaged Inductor. Need help and input!

Thread Starter

Pluto2020

Joined Sep 29, 2022
1
Hello All,

I need someone's expertise on this issue I'm having with an inductor that appears to be damaged. I originally found the issue when I gently tapped the inductor with a tweezer and it popped off with ease. This is not normal. As you can see in the attached pictures, the inductor looks damaged. I don’t know how this could have happened. I replaced it with another inductor and the cable worked. Now Im focused on this inductor and Im questioning whether the inductor itself could be bad or the pcba and how this could have happened (Bad soldering, electrical overstress, heat, etc?). What is it that Im seeing on that endcap of the inductor and pad? Has anyone seen this issue before? I've attached pictures and the schematic of the power supply. The inductor in the schematic is L1. Any help here would be appreciated

Inductor pad 2.PNGInductor pad 1.PNGPower Circuit.PNG
 

ericgibbs

Joined Jan 29, 2010
16,454
Bad soldering, electrical overstress, heat, etc?). What is it that Im seeing on that endcap of the inductor and pad?
Hi Pluto.
Bad soldering in production could have caused heat overstress

That bright dot is the internal connection of the pad to the inductor, the surrounding pad is left adhered to the PCB

E
Inductor pad 2.PNG
 

MisterBill2

Joined Jan 23, 2018
13,206
Given that there is a lot of information that we do not have, I will make some guesses here. First, I am guessing that this inductor is part of a much larger assembly in a purchased product that was made in mass production, and it was not a kit assembly or experimenter's project. The second guess is that the item had previously functioned correctly, rather than failed out of the package new. I am also guessing that the assembly has not been abused or handled roughly. I am also guessing that the pproduct containing this assembly is not a poor quality piece of junk.
Surface mount components are either hand soldered or reflow soldered in a reflow machine. If hand soldered, there could have been excess heat applied, OR the actual inductor device could have suffered a bit of corrosion prior to installation. If the inductor had been reflow soldered, there might have been a failure in the solder mask application due to a bubble in the mix. Or there could have been a bit of contamination on the circuit board.
 
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