[Sprint Samsung Galaxy S 4 Q&A, Help & Troubleshoot] oberon567:
PC not recognizing

Hi folks, hopefully someone here can help me out, my computer refuses to recognize my l720t.... but it isn't quite that simple...

I am an American living in India. A friend gave me his l720t (base OA3) in November when he bought a new phone. I was able to root it and unlock the sim, though I had to manually enter the APN details for it to work, but 3g data transfer, voice and SMS all work. Then another friend visited India and I lent him this phone and he used it for a month (voice and SMS only) and had no problems. He never connected to a computer.

Jump to now, I decide to try and get it up and running. The other phone I am using does not have a 4g connection on the bands available here in India, but most Samsung phones do, so I wanted to try and get the 4g working, but no matter what I do with the APN settings as soon as I switch to LTE it goes to digital roaming. I also want the wifi hotspot to work (I know there are various workarounds), and in general I wanted to remove the Sprint fingerprints form the phone, so I decide to flash one of the custom ROMs that others have found successful and see where that takes me. SO, I plug in the phone to my PC (Win10 64 bit, same as I was using in November when I rooted the phone) and.... nothing. It charges, but nothing else, computer doesnt even notice it, and when I go to USB tethering in the phone it says it is not connected to any USB device. So I uninstall the Samsung USB drivers that were already on the PC and reinstall them, and the first time I plugged in the phone, eureka! it worked, it was recognized, I could copy and paste files, excellent. Then I unplugged the phone and plugged it back in again.... and nothing. Sometimes Windows pops up a "your device failed to start" error. Other times it does nothing. Sometimes the phone says "You are connected to a dock," other times nothing. Never does it say I am connected to USB and give me the option to switch between MTP and PTP (though it did that one time when it worked). USB debugging is enabled, obviously. Other programs, like Kingo Root, do not recognize it as being connected.

I tried repeating what brought my previous glory, uninstalling and reinstalling, but no good.

In Device Manager, when I view hidden items, before I had uninstalled this most recent time Samsung would come up, but the driver listed for it was a default MS driver dated 2006, and trying to redirect it to the folder where the Samsung drivers had installed failed, it kept telling me no appropriate drivers were available there No that I have uninstalled Samsung no longer comes up, but "Android" comes up under USB devices, again with the default MS driver dated 2006, and again Device Manager tells me that it is up to date and doesn't let me negotiate any of the drivers from the Samsung folder.

So... what to do? Any ideas at all?

And as a secondary question, once I get the PC--phone connection working again, any advice on a ROM? The OP has Blisspop listed as the first in the list, but if you go to the Blisspop site there is no such ROM available any longer, it is just an empty folder. The OP lists various ROMs that work but not the pros/cons of each... Ideally I want something fully functional but as lean as possible. Ideally the Wifi hotspot would be unlocked by default, I would not need to "Activate the device" which I cannot do anyway, my 4g APN would connect and not give me a digital roaming nonsense, and all of Sprint's fingerprints would be wiped clean from the device.... Suggestions?

Thanks!

(edited to fix the baseband number)