I have an iPhone 5s. And it was stuck in dfu mode. As i try to restore it, i keep getting errors in itunes like: 40, 3194. And now it's still stuck at dfu mode (Complete Black Screen) and it wont even turn on even using force restart (Power + Home) for 10 - 30 sec. Please help.
What ios firmware that you are trying to restore?
Try connecting to pc or laptop make sure you have the latest version of itunes. plug in your ios device and hold home button. And try it to restore.