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I have a Creative speaker board for repair. I'm confused with replacing the capacitor. I have desoldered the capacitor and brought a new one. The circle in the PCB which represents the cap has a dark and white part. Which one is positive?

PCB photo

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    \$\begingroup\$ Compare with the marking on and below e.g. C11. \$\endgroup\$ – Turbo J Nov 4 '13 at 12:39
  • \$\begingroup\$ which part is positive dark or white? \$\endgroup\$ – techno Nov 4 '13 at 12:40
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    \$\begingroup\$ Whichever way the old one was mounted, of course. \$\endgroup\$ – Olin Lathrop Nov 4 '13 at 12:55
  • \$\begingroup\$ @techno Why don't you put spaces after punctuation? I've edited your question to have them, but you should include them for future reference. \$\endgroup\$ – JYelton Nov 4 '13 at 18:10
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The dark one is the negative. And you could see it by yourself on the two capacitors near to the missing one! If it is visible on so bad quality picture, it should be obvious for you.

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When still in doubt, check the copper side. If one of the connections is to a very large plane, which might include screw mountings, that will most likely be the negative side.

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  • \$\begingroup\$ +1 for checking. I've seen PCBs where the dark part of the circle was in fact positive. To make things worse, it was set up that way only for one particular capacitor. If there is any doubt at all, check! \$\endgroup\$ – AndrejaKo Nov 4 '13 at 14:54
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Electrolytic capacitors usually have a stripe down one side (with minus symbols on it) that identifies the negative leg.

You have several other capacitors in-situ on that board - and can see the light/dark board marking under them. Use them to identify light or dark as negative.

From the pic, I believe dark is negative.

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