Compuer shows no sign of tablet connection (SGH-T779 Samsung Galaxy Tab 2 10.1 for T-Mobile) How can I get my computer to recognize I have attached my tablet?  I have tried every trick online with no luck.

Couple notes:


No indication at all from computer that a tablet is plugged in (No yellow exclamation marks in device manager, no sound upon plugging in)
I have tried multiple cables ( I believe this may be a hardware issue), multiple usb ports
I have tried all sorts of driver install methods as well as usb debugging modes
The only indication I get is a red x on the tablet over the battery when plugged in.  The tablet charges fine when plugged into the wall charger.
My other galaxy tab 10.1 original communicates with the computer fine ( I have since reformatted the tablet and computer and have tried multiple computers)


Currently using:
- Thinkpad T61 with aging battery
- Samsung Galaxy Tab 2 10.1 (SGH-T779) T-mobile
- Windows 8 (Have tried with a fresh copy of Windows 7)
- Running Android 4.1.2

The only indication I have gotten from the pc that the tablet was plugged in was the mouse changing from an arrow to a thinking symbol for less than 1 second.  I feel as though I have tried everything and it is a broken port on the tablet.  It charges fine when the tablet is off.

Overall, I wish to root the tablet to put a custom rom on it.  I have tried rooting the tablet using various apk's w/out a PC but have had no luck (I will probably post another question about troubleshooting root process with no PC).

Thanks in advance
This might sound crazy, and I do not recommend anyone try it, but...

I had tried cleaning the female charging port on the tablet with alcohol and q-tips and had no luck.  I decided to use the tip of a mechanical pencil (metal tip) to scrape the contacts to see if they had build up.  I put the metal tip in to scuff them up and (since the tablet was on), a huge spark shot out of the tablet and it immediately shut off.  I assumed I fried it, but it turned back on... ...and worked perfectly from that point on.  It was then recognized by my computer.  

Obviously, this is somewhat crazy and I don't recommend people try this.  I had tried every method of connection from the far ends of the internet with no luck.  Somehow it worked normally after this point.  Could the spark/firework show have cleaned the contacts?  I know that some pins are for charging (which it would do fine) and other pins are for data.

My tablet is now working.