Why do you need a power inserter for a SWM system?

It’s that little grey box that the installer told you you couldn’t unplug, ever. We call it the PI-29 Power Inserter, and its purpose is to provide power to the electronics inside your dish or multiswitch. If you’re new to DIRECTV, you might have wondered what it does, and if you’ve upgraded from an older system you might have wondered why you didn’t need it before and you do now.

The dish on your roof is a lot more than just an antenna. The part on the front is called an LNB, meaning “Low Noise Block.” It takes the signal coming from the satellites and amplifies it. This takes power, of course. In the case of older systems, your satellite receiver provided that power. In newer systems the power comes from the power inserter.

Using a separate power inserter has its advantages. First of all it provides enough power that the dish can not only amplify but do other tricks. Using a single-wire system is tricky and it requires that all the signals sent out don’t interfere with each other. This requires more power. Also, using a single power inserter means that all the receivers don’t need to have power supplies big enough to power the dish. This makes it possible to have smaller boxes like the DIRECTV H25 which can only be used in a SWM system. So, by having a single power inserter you almost always save energy compared to having two or three (or more) full-power receivers in your home.

If you accidentally unplug the power inserter, the world will not come to an end. Most likely you will start getting 771A or 775 errors on your receivers, and at some point the picture will probably freeze and go black. While plugging the power inserter back in will solve this, it’s best to reboot the receivers as well, after waiting 30 seconds or more for the power inserter to get everything balanced again.

Some people have reported running without a power inserter for an extended length of time but it’s not recommended; even if it does work (and it almost never works) it will burn out the LNB as it tries to use the little power it can get.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.