The USB jig for Samsung devices can be immensely useful. When used properly, they force a Samsung device into download mode so you can flash firmware over Odin and restore it to working order. It is especially useful when you’ve broken pretty much everything and need a fresh start. Additionally, it completely resets your flash counter. There is an application that can do this called TriangeAway by XDA Elite Recognized Developer Chainfire, but it’s always good to have additional options.
If you find yourself wanting to enter download mode easily, you can build your own USB jigs. While making your own is nothing new, there is now a thread posted with a step-by-step photo guide to creating your own jig. It isn’t overly difficult, but does require some soldering. So if you do attempt it, be sure to read all the instructions first to make sure you know what you need to do. You can find the thread here.
Of course, whether you buy one or make one, you should also know how to use one. XDA Senior Member mattcfk has released a very generalized FAQ to help you use the USB jig to do anything from removing the yellow triangle to restoring a bricked device. You can find the full FAQ and support thread here.
Of course, if all else fails, there may be a forum member in your area that’ll let you borrow their jig for a one-time use. XDA Senior Member saywhatt has compiled a list of users around the world who have a USB jig that would be willing to meet up and let you use it. Of course, as with any meeting with a stranger, be cautious. If you’re looking for someone in your area, you can find that thread here.
Whether you build it, buy it, or borrow it, these USB jigs can mean the difference between a paperweight that you have to return and a fully functioning phone. If you own a Samsung device and don’t have one, you should look into it. They’re definitely useful little tools._________