Does the tablet indicate that it is charging when connecting a charger to the USB port or when connecting to a PC's USB port?
If not see below regarding opening the tablet
If so this proves that 2 of the 4 connections of the USB port are OK. (The battery and earth connections).
Have you tried a different USB cable, or different USB port on the PC or a different PC when connecting the tablet?
If so and it still doesn't work, this indicates that there is a problem with either the USB port in the tablet (if there is a problem with either the data-ve or data +ve connections then there will be no communications possible with the tablet via USB) or the USB controller IC in the tablet.
Use a strong light and a magnifying glass to visually inspect the USB port. Check that all the pins are there, especially the middle pins and that they are straight and parallel with each other. Also check that there is no dust or lint in the port.
If there is lint etc. in the port, use a vacuum cleaner to remove the debris. Do not use a metal probe to try and remove it, you may cause damage to the port and the tablet. If vacuuming doesn't work , try a wooden toothpick to very gently clear the port.
If the USB port seems OK, here is a link to the Ifixit guide(s) to repair the tablet. It is handy as it shows how to open the tablet. Once open you can inspect the USB port to see if it is loose at all on the motherboard. If it is loose then as it is most probably a SMD (Surface Mounted Device) type USB connector, you will need the requisite tools and skills to re-solder it back onto the motherboard. As you can cause more damage than you already have if you don't know how to do this, I suggest that you contact a reputable, professional mobile phone repair service and ask for a quote for a repair.
Trio Stealth G4 Repair
Alternatively you could always try using Bluetooth or WiFi and see if that will work for you. BT here WiFi here