[Galaxy Grand Prime Q&A, Help & Troubleshooting] peteramares:
Hello folks,

I ran into a poblem with my old Samsung Galaxy Grand Prime Plus. 3 years ago I was messing up with the phone and I ran into an invalid IMEI problem. As I was a real newbie, I brought it straight to a friend of a friend of a friend who had a phone shop, and he fixed it for me.

Everything OK until last week, when I suddenly realized that probably the guy had flashed the wrong IMEI to it, mistyping 2 numbers of one of the two IMEIs.

Currently, I then have a perfectly working phone, but the IMEI is incorrect and I need to fix it.

I don't have the box anymore, but luckilly the numbers under the battery are perfectly clear and readable, although this is quite an old device.

As the shop of the guy who did the work is long gone, I started to look around for instruction on how to deal with the problem, and I followed all the possible tutorials, but apparently I'm not able to fix the issue.

I just know it can be done, as this was done to the very same phone in the past, creating the problem. I just do not happen to know how he did...

Here's what I tried so far:

1. APP: Mobileuncle Tools

Whenever I tap onto "IMEI Backup Restore (MTK)" I get an error message that says "No support".

2. APP: MTK engineering mode

I open the app, and whenever I tap onto "MTK Settings" I get an error message that says: "Cannot find EngineerMode App - Mediatek chipset is mandatory and stock ROM must be installed".

I tried both Mobileuncle Tools and MTK Engineering mode with 3 different ROMs downloaded from different sources, before and after rooting the device with Super SU, but to no avail.

3. With any xposed module

This could be a solution... but not a real one.

At least according to all the documentation I found (also here on the forum), any xposed module like "IMEI Changer", "chamaleon", "device changer", "hijack suite free" etc only mask the IMEI in front of other apps, but do not really change the IMEI of the phone.

So basically I would still have a phone with an illegal IMEI on it.

Not ideal: this is not what I am looking for.

4. IMEI Maker and IMEI Repair

I followed the tutorial I found here:

https://xdaforums.com/showthread.php?t=2399037

I encounter no errors at all, and TWRP shows a clean log, nothing seems to be wrong. But after flashing the new IMEI, nothing changes: with *#06# I can still see the wrong IMEI there.

The file in data/nvram/md/NVRAM/NVD_IMEI/MP0B_001 just remains the same, dating 2016, and does not get replaced by the new one.

I tried to replace the file manually, using ROM Toolbox Lite. At the beginning I could not delete the original MP0B_001 file, even after changin permissions to 775. It kept saying "File deleted" but the file remained there.

I then installed BusyBox Free, and it did the trick: now using ROM Toolbox Lite I definitely can delete the MP0B_001 file. The problem is that the original file keeps coming back again and again, after every reboot.

Nevermind if I place the new MP0B_001 file in the folder copying and pasting it or flashing it with TWRP, it will get overwritten by the old file with the wrong IMEI.

5. Flashing a Combination ROM

I didn't find a specific tutorial for this one, but I just tried to flash the combination ROM and see whether I could get any luck touching things in there.

No luck!

6. With SN write tool (windows software)

Here the big problem is, I can't find the BP file anywhere.

No AP_BP_database seems to contain the BP file for the MT6737T (that is the chipset of the G532F). As I am writing, I am thinking about trying to use a different BP file, from a different chipset. This will probably won't work, but after trying all of these, I mean, why not...

I also tried to look for the BP file into the folder /system/etc/mddb/ , as advised here: https://forum.hovatek.com/thread-11609.html . I looked for ir with any of the 3 different stock ROMs I tried to install. Yet again, absolutely nooooo luck here.

7. MTK Droid Root & Tools (windows software)

This won't even connect to the phone. That is, whenever I connect the phone to the PC, I get the following errors:

" --- Estructura de ROM desconocida, no se puede hacer backup ! "

That would be something like: "Unknown ROM structure, cannot perform backup"

The device gets recognized (hardware, model, build number...), so it should be a problem of drivers, cable or USB port. Also because I used the same setup to install all the stock ROM, TWRP, Super SU etc...

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And here I am. After one week of try and fail, getting tired of all this!

I'm surprised on how persistent that wrong IMEI is, as I can't get rid of it in any way.

Do you have ANY kind of idea of what can I do?

As the points 1, 2, 4, 6 and 7 are specifically advised for MTK chipset. I'm starting to doubt that this is an MTK chipset altogether!!!

Thanks for your help

Peter