Is this a Shielded Inductor?

Thread Starter

rustedmetal

Joined Jun 7, 2020
6
I'm attempting to repair this very old laptop without any schematics as it has been impossible for me to find one. The laptop has no power whatsoever when plugged in. I've tested the charger cable and charger port and the Voltage was good. When i moved on to the module in question one of the three contacts i tested had no V, the upper right contact i haven't tested because my multimeter doesn't fit. Are any of the contacts in this module suppose to have 0 V?
inductor.jpg
 

prairiemystic

Joined Jun 5, 2018
234
It looks like a common-mode choke, with 4-pins. Not shielded but with a plastic case around it?
I would check the 8A fuse and the diode with a big chip taken out of it.
 

mcardoso

Joined May 19, 2020
221
It looks like a common-mode choke, with 4-pins. Not shielded but with a plastic case around it?
I would check the 8A fuse and the diode with a big chip taken out of it.
I agree with it being a common mode choke, but likely with a pressed ferrite material around the outside. Commonly used with inductors and other similar wound applications.

https://en.wikipedia.org/wiki/Ferrite_(magnet)

See the soft ferrite section.
 

Deleted member 115935

Joined Dec 31, 1969
0
Noise has to be killed at the source,
else it radiates.

If it was up to the power brick to kill the noise of the laptop, then the cable between the laptop and the power brick would radiate. You might have seen the lumps around some cables, which are retrofitted when the item fails Em testing, and are there to stop the item radiating up the cable.

hence the choke on the PCB, to stop the noise getting out side.
 
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