[T-Mobile, Samsung Galaxy SIII] johnx818:
Hello XDA!

I don't want to post a wall of text (not that tall of a wall, at least), so, I'll try to get to the point quickly. And yes, I have done a lot of searching, both on XDA and Google, and that will be proved soon enough with the solutions that I've tried so far.

The problem I'm currently experiencing is when I connect my phone to my computer, it charges but it isn't recognized. There is no USB notifications, no phone in My Computer, and no Windows pop up, whether it's a pop up asking me to install drivers or an unknown device has been connected, nothing. Mind you, everything has been working flawlessly, this just randomly, and I really do mean randomly, started happening. The phone has never been dropped and there is no water damage. I'm still using the USB cable that came with the phone. And, if it matters, I'm rooted, running the leaked LI8 JB ROM, stock kernel, and UVLEM baseband.

Here's a list of said solutions that I've tried so far:

Using a thin paint brush, wet the tip a little with alcohol and tried cleaning out the USB port

Connecting to a different computer, connecting with a different cable, connecting to any other USB ports on the computer

After making Nandroid backup: Data wipe/factory reset, flashing a different ROM

Remove Samsung USB drivers and reinstalling, also tried installing Samsung Kies

Uncheck USB debugging and restarting, checking USB debugging and restarting

Dialled *#7284#, select Modem, then reselect PDA, changing Qualcomm USB settings and changing it back to MTP + ADB

Turn off phone, remove battery for 30 sec, reinsert and boot up (soft reset to reset internal circuitry as described by a Samsung live chat service tech)

I might've left out a couple, but please do enlighten me of methods that you might know, I'll be sure to try it or let you know if it's already been attempted.

..also, when connected to my PC, under Settings > Battery, it shows "Charging (AC)" IIRC, this should be showing "Charging (USB)".

This next attempt stood out to me. I decided I would try and go back to the stock firmware, one where I would have to use Odin3. So, I put the phone in Download Mode, open up Odin3, connect the phone, and I get a pop up in Windows! It's trying to install drivers, and fails. I can't flash the stock Samsung firmware if I wanted to, even for warranty purposes. I do currently have the USB drivers installed, but my PC hasn't gone through the driver installation for when the phone is connected to the computer. So, I'm assuming that is why this is failing? I'm not entirely sure. But, when I saw this, I unplug the phone and plug it back in numerous times, to rule out that this might be a hardware problem. And, every time I plug it back in, it tries to install the drivers but fails. So, it's detecting my phone in Download Mode. I reboot and hope that it will detect normally, but no, it doesn't...

As a last resort, I went to Samsung.com and chatted with a service tech, he runs me through two procedures that I haven't done, the 'soft reset' and a 'master reset', which is done through Settings > Back up and Reset > Factory Data Reset. Neither worked, so, he then checks my IMEI and finds that I am still under the 1 year warranty and files a ticket for repair service. I asked him if there is a replacement warranty and he says that is done through my service provider (T-Mobile) with the Premium Handset Protection service, which I didn't add. Not because I didn't want to, but I can explain in later posts if someone is interested in why it wasn't added. So, now I have the return label in my inbox ready to be printed, taped onto a box containing my phone, and sent out. But, I can't go through with this because I have a custom ROM on the phone. There is no counter because I've already used Triangle Away, AFTER this started happening.

I am completely stumped... Any information is greatly appreciated!

EDIT: Also, I've disassembled the phone to check the MicroUSB port to see if any pins or prongs might've came loose. Everything is in tact.. I also wanted to see if the MicroUSB port was replaceable because I was able to find a spare MicroUSB ports on a website. But, it seems that the port isn't easily replaceable. It doesn't look removable, and I'm uncertain if it can be de-soldered to solder a replacement one on. Also, some thing caught my eye when I had it disassembled. There were two components of the phone that had SGH-I747 imprinted on them. I wasn't able to take pictures as I was in a rush to get it put back together, but thought it was of interest to bring up.