# Tips to build computers: Power Source

**URL:** <https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640>\
**Category:** Factual Questions\
**Created:** [April 25, 2007, 8:34pm UTC](https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640 "2007-04-25T20:34:11Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![SweetHomeColorado](https://avatars.discourse-cdn.com/v4/letter/s/d26b3c/32.png) [@SweetHomeColorado](https://boards.straightdope.com/u/SweetHomeColorado)\
**Post date:** [April 25, 2007, 8:34pm UTC](https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640/1 "2007-04-25T20:34:11Z")

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What is the method to the madness when building a new computer and plugging in the power source to the components? Different colors obviously represent different voltages (right?) I know the general rule of thumbs is red- hot black- ground. Does this remain the same?  
Any other tips when connecting the power to the pins?

Thanks in advance!

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**Author:** ![Saltire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saltire/32/553_2.png) [@Saltire](https://boards.straightdope.com/u/Saltire)\
**Post date:** [April 25, 2007, 8:45pm UTC](https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640/2 "2007-04-25T20:45:13Z")

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All the connectors on a power supply should be foolproof, in that there will be a particular plug for a particular power need, and can only be plugged in the correct way. I know that each individual wire serves a particular purpose, but I don’t know the specifics because I have no need to.

If you are working with a power supply that isn’t supplied with its own plugs already wired, you’re way past my knowledge. I can’t imagine why you’d want such a thing when the prewired ones are cheap and plentiful.

[edited for a minor typo]

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**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\
**Post date:** [April 25, 2007, 8:48pm UTC](https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640/3 "2007-04-25T20:48:09Z")

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[Pin assignments and color codes.](http://www.technick.net/public/code/cp_dpage.php?aiocp_dp=pinconmth_atx_power)

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**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\
**Post date:** [April 25, 2007, 9:08pm UTC](https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640/4 "2007-04-25T21:08:19Z")

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Don’t ever trust wire colors. Not everyone follows the standards.

As was previously mentioned, all of the common connectors are keyed so that you can’t easily screw them up. If you are using excessive force to put a connector in, chances are you’ve got it the wrong way around or are using the wrong connector.

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**Author:** ![Crescend](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@Crescend](https://boards.straightdope.com/u/Crescend)\
**Post date:** [April 25, 2007, 11:39pm UTC](https://boards.straightdope.com/t/tips-to-build-computers-power-source/401640/5 "2007-04-25T23:39:36Z")

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As was said earlier, power connections inside a computer are determined by connector geometry. The exception to this is when you’re doing something weird, such as shorting pins (such as the ATX-power-on trick), or soldering on a custom connector.

If you do either of these, be very careful and have a multimeter handy.