[Android Q&A, Help & Troubleshooting] manutest:
Hi!

I recently bought a NUU X5 mobile from banggood. Sadly it went out of stock and they only sent me the Indian version instead of the Global one I originally ordered...

Anyway it worked ok but I wanted to root it by installing TWRP and then Magisk, which I have done a couple of times with other phones.

What I did was:

>fastboot oem unlock
...
(bootloader) Start unlock flow

OKAY [ 26.177s]
finished. total time: 26.179s

>fastboot flash recovery TWRP.img
target reported max download size of 134217728 bytes
sending 'recovery' (5944 KB)...
OKAY [ 0.274s]
writing 'recovery'...
OKAY [ 0.149s]
finished. total time: 0.425s

Sadly, I didn't backup the stock recovery before with the SP Flash Tool. I didn't think it was a big deal and I never had problems with it, though the TWRP is not an official release. But I thought in the worst case the recovery does not work but what really happened after that:

The mobile went into a boot loop. And I cannot get into the recovery or even fastboot any more!

I didn't know the recovery is even used during a normal boot!

I think what I would need is a stock X5-IN-01 firmware.

The guys at needrom.com only have

X5-AM-02 - full_hct6750_66_n-user 7.0 NRD90M

X5-EU-01 - full_hct6750_66_n-user 7.0 NRD90M

and they also want money for me to download it!

However I found in the internet

Nuu_X5_MT6750_20170308_7.0.zip

which turns out to be the X5-EU-01 firmware. I would pretty much even prefer this firmware over the indian version to get all LTE bands, but for now I would be happy if I even got the damn thing to boot again :)

So I started experimenting with the SP Flash Tool which can still access the phone.

The scatter file that is delivered with the firmware does not match the actual setup of the phone.

The EU firmware has an extra partition "persdata" which the IN firmware does not have.

I created a modified scatter file which matches my partitions. (I got the partition info from the GLB_xxx.log trace file from the SP Flash Tool). Then I backuped everything (too late for the recovery...).

Then I flashed only the recovery from the EU firmware. To my surprise, the firmware now displays the boot screen again (was totally black and no backlight before)! But it does not boot, after quite some time it resets so it's a much slower bootloop now.

I then tried to flash different partitions with the EU firmware stuff, I ended up flashing everything except the preloader and the md1dsp (which I read should maybe not be touched?). I'm not touching the preloader because I think if it is gone, I cannot get in with SP Flash Tool any more, is that right?

Anyway, when I flashed everything except preloader and md1dsp, the display was black (no boot screen), but backlight was on. The phone was actually booting! ADB was possible but no working screen.

Then I tried flashing back one by one the backuped IN partitions. It ended when flashing the "lk" partition. With the original IN "lk" partition in place, I have a boot screen but no boot. With the EU "lk" partition, I have a non-working screen and boot. What does the "lk" partition even contain?

Now I need your help guys!

What to do? I cannot find the IN stock fw anywhere. Is it possible to download it from the NUU OTA update server? Or does anyone have such a phone and can provide the stock recovery? Or should I erase everything reformat and put in the complete EU firmware including new preloader and persdata? To my knowledge the hardware is the same, at least it has exactly the same specs.

Any help is very much appreciated.

Manu