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Here is PCB taken out of Eplutus portable DVD player. Broken SMD inductor is soldered out because it is cracked in half. It is L 46. I need to know its parameters/values.

enter image description here

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  • \$\begingroup\$ Is it not rattling around inside the case somewhere? \$\endgroup\$
    – vir
    Oct 16, 2023 at 21:32
  • \$\begingroup\$ The pads for L46 do not appear "factory." They are not flat, as though the component was not populated (DNP or NF), nor is there signs the component burned, chipped, or failed (fragments present). Instead, the pads and flux residue seem to indicate the component was removed manually. Which leaves the question: Did you or someone else remove L46 and lose it? \$\endgroup\$
    – JYelton
    Oct 16, 2023 at 21:37
  • \$\begingroup\$ Why did you remove my edit which helped readers find the missing component in your image? \$\endgroup\$
    – JYelton
    Oct 16, 2023 at 21:48
  • \$\begingroup\$ unintentionally i think. How to restore it I would know. \$\endgroup\$ Oct 16, 2023 at 21:51
  • \$\begingroup\$ You don't have to retain it, but you could add an arrow/circle to the image or something. It took a while to locate. \$\endgroup\$
    – JYelton
    Oct 16, 2023 at 21:52

1 Answer 1

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L46 appears to be directly connected to the barrel jack (power input) connector on that PCB. It could be an inductor intended to act as a series choke to limit digital or switching noise into the power supply.

Your comment added a key piece of information:

...because it cracked in half...

This suggests that it may have acted like a fuse in an over-current situation. The tiny wire inside heated and caused it to crack, creating an open and disconnecting the device from power. This doesn't mean that it saved the device, there could be other components damaged from whatever happened. Perhaps the wrong power supply was connected, or there was a power quality problem. Or maybe a downstream component failed and pulled too much current.

With the admonition in mind that the failure could be more widespread, you could try replacing L46 with:

  • 1 or 2.2 µH inductor is a common value for this sort of application. Just be sure to size it appropriately for the current (check device enclosure or power supply, if you have the correct power supply for it). For example, if the device draws 200 mA, make sure the inductor is rated for that as a minimum.

  • 0 Ω resistor/jumper or bit of wire, effectively eliminating its function from the board but providing a connection to power to at least determine if the device still functions.

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  • \$\begingroup\$ I used the right ac/DC adapter. Input : AC 100 - 240 V 50/60 Hz. Output : DC12V - 1,5 A \$\endgroup\$ Oct 16, 2023 at 22:17
  • \$\begingroup\$ Another possible scenario is that the DC jack took some excess stress during plug insertions or removals. The chip inductor is located close to a diagonal leading away from the 90 degree intersection of the jack's rear & side pins. Lifting or twisting of the jack could have caused a torque between those pins and along the diagonal. With the chip soldered right across that diagonal it would not take much stress to crack it in half. Similar to the answer from JYelton the inductor value is likely not critical, though I'd replace it with a free standing leaded ferrite coil of several turns. \$\endgroup\$
    – Nedd
    Oct 17, 2023 at 3:38
  • \$\begingroup\$ What smd inductor would you recommend for my device? aliexpress.ru/item/… \$\endgroup\$ Oct 18, 2023 at 16:39
  • \$\begingroup\$ Anything from a reputable manufacturer (Murata, Coilcraft, Samsung, TDK, Bourns, etc.) and vendor (not Aliexpress!) with a datasheet that fits the footprint (0805, 1206... I'm not sure what it is without being able to measure). Since we don't know the original part specifications, it is impossible to recommend anything too specific. \$\endgroup\$
    – JYelton
    Oct 18, 2023 at 17:38
  • \$\begingroup\$ Could you please tell me what diode schottky replaces my smd (ON) 546 B 24 ? Analog I mean. These items are hard to find. \$\endgroup\$ Nov 15, 2023 at 19:48

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