What is a capacitor?

Posted On: June 15, 2014 Categories: Tech Tools,

A capacitor is a small electrical component on your motherboard that can perform various functions. First of all, capacitors condition DC voltage to the components and thus provide a steady power supply. Electrical components are very sensitive to voltage swings, and as such a power spike can kill those expensive parts. We don’t want that now, do we? Therefore a capacitor is placed inline to the component, allowing for absorbing of spikes and supplementing valleys, keeping a constant power supply to the component.

Second, a capacitor can store an electronic charge to be discharged at a later date. Think of a camera flash for example. A typical battery cannot release large amounts of electrons at any given point in time, and therefore a capacitor is installed into the camera to build up a charge, which is then released all at once for the flash. Remember when you couldn’t take a picture for a few seconds when using a flash? The capacitor needs time to build it’s charge from the battery, and therefore it is not ready to discharge yet.

The most common use of capacitors on motherboards is for conditioning power to the components, and if the capacitor is bad, it will not condition the power. If you put a suck on the power, such as engaging in graphics intensive applications, the capacitor is drained of its reduced capacity and the component loses power, thus shutting down the PC or freezing the screen.

What can I do if the capacitors are bad?

You have three choices, assuming that your system is out of warranty:

  1. Find and solder on a replacement capacitor. This is generally not recommended, as someone who does not know what they are doing or have the proper tools will probably create more problems than they cure trying this approach.
  2. Send the board in for capacitor replacement. If you have a pre-built system, this may be the way to go, particularly if your system is still under warranty. Tell the customer service rep right away you have bulged capacitors and you will forego a lot of troubleshooting by you and the tech. They know this is a problem and will send a replacement and a tech to changeout the board. If you bought the board and do not want to RMA it, you can also send this into several specialty service folks to have them replace the capacitors.
  3. Replace the motherboard. If this was your own purchase and you have the original box, ask the manufacturer for an Return Merchandise Authorization form. Send in the old board, and they will more than likely send out a replacement, and all you have to pay is shipping. Most do not do cross-shipment, so you will be without a PC for a while! Maybe you should take this opportunity to upgrade to a newer chipset, anyway!

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