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It looks to be a cap,and i can measure 2.2uF using my multimeter.From the circuit the cap is in parallel on the positive side of where a ac/dc power source gets plugged in and goes into the Vin on a step down converter.Any input is welcomed thanks.https://s10.postimg.org/spocur0ft/unknown1.jpg

enter image description here


marked as duplicate by Voltage Spike, Enric Blanco, PeterJ, DoxyLover, Dmitry Grigoryev Jun 20 '17 at 14:55

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    \$\begingroup\$ Chances are that it could be a reverse polarity protection diode as well. The 2.2uF you measure might be in parallel with it but present elsewhere on the PCB. Try the diode test and see if there is a diode present. That's no guarantee either as the DCDC converter might also have a diode. Desolder it and then measure, only then you know for sure. Package type is more like that of a diode. \$\endgroup\$ – Bimpelrekkie Jun 13 '17 at 14:49
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    \$\begingroup\$ the stripe on the side makes it look like a diode... \$\endgroup\$ – dandavis Jun 13 '17 at 14:50
  • \$\begingroup\$ It looks very much like a diode to me \$\endgroup\$ – MCG Jun 13 '17 at 14:50
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    \$\begingroup\$ nteinc.com/specs/600to699/pdf/nte633.pdf \$\endgroup\$ – Shamtam Jun 13 '17 at 14:55
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    \$\begingroup\$ @Shamtam It could be a clone of the same diode by another company (such as a million makes of 1N4001), but it's certainly a very very likely match. \$\endgroup\$ – Majenko Jun 13 '17 at 15:07

Your photo makes it look like a diode in a SMD package similar to the common SOD-323. With the dimensions provided (4.2 x 3.5mm) and the note that the leads hook under the component, it appears to be a SMB (DO-214AA) package. There are a few things that suggest this:

  1. Surface-mount capacitors are generally made out of ceramic: they are gray-to-brown in color, unpolarized, and look like this.
  2. Diodes, because they're semiconductors, have to be packaged, usually in black plastic.
  3. Because diodes are necessarily polarized, they always have a bar marking the cathode.

Edit: Changed prescription to SMB package.

  • \$\begingroup\$ the body is around 4.2mmx3.5mm,which looking at SOD packages it looks more like a SMA based on the size and the leads are pointing straight down and dont bend like the sod packages do.its almost like half a square.sod packages \$\endgroup\$ – T. A. Jun 13 '17 at 15:56

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