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How to identify capacitors

Crunchry-Boy

Sep 23, 2020
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I need some help identifying some very small capacitors. I was wondering if a multi meter would be useful in this process and what other info is needed? Really not even sure that this is the right place for these questions but thanks anyway.
 

bertus

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Nov 8, 2019
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Hello,

What kind of capacitors are you talking about?
Do you mean the SMD capacitors?
SMD capacitors

Bertus
 

Crunchry-Boy

Sep 23, 2020
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I’ll post a pic later it’s a Game Boy Advance SP PCB that I’m working on it’s about pin tip size. I think it’s ceramic
 

Ylli

Jun 19, 2018
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That link is to an 0805 part. That means it is 0.08" long and 0.05" wide. That is a fairly big part, certainly more than 'pin tip sized'. These parts are also available in sizes 0402, and 0201. The latter being 0.02" long and 0.01" wide. That is perhaps 'pin tip sized'. If you have a high powered microscope, some 01005 and 008004 parts are available.
 

bertus

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Hello,

As @Ylli said, smd capacitors are available in many sizes.
For comparison of the sizes, I have here a chart:

smt_sizes_based_on_original_by_zureks-svg.png

Bertus
 

Harald Kapp

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I was wondering if a multi meter would be useful in this process
If the multimeter has a capacitance range it could be used. But you'll have to remove the capacitor from the PCB to get a useable measurement. But then again: Ig the capacitor gives a reasonable measurement it is probably o.k. and you can solder it back. But if the capacitor does not give a reasonable measurement (e..g because it is internally short circuited or one of the endcaps has gone open circuit, the measurement will tell you only that the capacitor is defect. You will need a schematic or a bill of materials to know which value to use for replacement.
Sometimes you may be able to read the nominal value off the capacitor. If you find an inscription in the form of a three-letter code like 102 this can be used to identify the capacitance. However, Automatic pick-and-place machines don't care about top or bottom of such an SMD component when placing it onto the PCB. Therefore the inscription may be on the bottom side of the capacitor (versus the PCB) so you would have to de-solder it to be able to read it.
Having two soldering irons or an SMD (de-) soldering tip will come in handy for this task. Otherwise you risk overheating the component, thereby destroying a possibly good component.

What makes you think this particular capacitor may be defect?
 
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