Looks like yet another frankenphone. Wish I knew where these things were coming from!
Its hard to tell you what to do, but if it currently had MD5 on there, you probably need to stick with T999 firmware. Well, maybe....
Install terminal emulator and enter this:
This will tell you what the firmware is. You cant judge by the rom or baseband.
Anyway, almost every time ive seen these things, the recommendation is usually to see if you can return the device. Theres just too many questions and things that dont match up. If you plan on using it as is, and never care about updates and such, I guess it might be ok, but otherwise theres just too great a chance for future problems!
For starters, there's no such thing as a GT-T999. And If download mode says its an I747, id guess youre using the I747 base firmware/bootloader. However, your system and baseband are from the T999 firmware, so we can be pretty confident that flashing I747 firmware will not work. But you probably can only flash I747 firmware because thats what your bootloader appears to be! Very confusing, very messed up, I know! Its highly possible, judging by the GT-T999, that it might be a chinese knock-off.
It may or may not help, but install Phone Info - Samsung app. Then let me know what it tells you. I dont think theres going to be a lot we can do though, but ill be glad to take a look anyway.
Yup, its exactly as I expected! I747 bootloader/base firmware with T999 system and modem. These are not things that should work together and it also means there is no safe way to update your firmware. LI5 sounds like its really old btw. But tbh, I dont know if its even a real build number! I can say you will not be able to run TW kk roms and might not be able to run 4.3 ones as well. CM/aosp, im not sure about, but I know they were known to be really buggy on older firmware.
If it is an option, I strongly suggest seeing if you can get a refund. May I ask where it was bought from? I think whenever we run into these we need to start letting people know not to purchase from those sellers. For one, to protect folks from having this happen to them, but also to try and discourage this type of business practice (if you even want to call it that!). Its almost as bad as people who sell devices and then report them lost!
---------- Post added at 06:08 PM ---------- Previous post was at 06:06 PM ----------
Just checked and LI5 is a real build, but it is old. 4.1.1
I dont use non touchwiz roms, but I do remember they all started requiring certain bootloaders nrcsuse they were encountering too many bugs on older ones. I dont know any details though.
Id imagine youll encounter issues flashing any rom thst has the assert check. It checks to make sure you have a certain bootloader, and most here will be checking for T999 builds. Since yours has the I747 bootloader, it may cause trouble flashing certain roms.
That and you wont be able to easily or safely update the firmware...
Not sure theres much that could be done since it came from a pawn shop though.