OTG support through USB
How can OTG function for the usb port be activated so that USB drives and other devices can be used through the usb port?
Usually you need a compatible OTG cable or dock for your device. An OTG cable is different than a normal USB cable. An OTG cable has the sense pin shorted to the ground pin, while a normal USB cable does not. Some manufactures may use a resistor of a certain value to short the sense pin to the ground pin. This tells the device to enter USB host mode when an OTG cable is connected. So if you have a compatible OTG cable you should only need to plug in the cable for the device to activate USB host mode (OTG). Plug in your USB device to the OTG cable first then plug the OTG cable into your tablet. If this does not work then you may want to let me know what version of Android you are running and what kernel it uses. You can find this information in the settings menu under About tablet. Or you can do a search to see if the kernel you are using has OTG function or not included. I am going to guess your kernel does have it but it may not hurt to check if you can not get the tablet to enter USB host mode(OTG). There are also some apps from the Google Play Store that may help troubleshoot your OTG issue, just type OTG into Google Play search to find some. Hope this helps.
The Galaxy Tab 4.7.0 only supports OTG on the LTE version… Sorry guys…
check for power supplied by the phone through the OTG Cable
Try starting the tablet in safe mode and check if it works OK.
If it does a "downloaded" app is the cause of the problem.
If still no good use a magnifying glass and a strong light to visually inspect the USB port to make sure that there is no dust or lint trapped in the enclosure and that ALL the pins (5) are there, (especially pin 4 as this is the 'sense" lead) and that they are straight and parallel with each other.
If there is anything trapped in the port enclosure preventing a good electrical connection, do not use a metal pin or probe to get it out, use a wooden toothpick or suitable plastic probe to gently pry out the obstruction.
Its root fault… Stock kernel fixes all