Constant reboot issue on Mi 9 SE (grus)

[gustavofalcao1]

Hello everybody. I'm having a very annoying problem with this smartphone for a while.

Smartphone: Xiaomi MI 9 SE (grus)

Initially it was restarting a few times, when it was in standby, after some time it started to restart and when it came back it had less battery than before.
So even though I thought it wouldn't work, I tried to solve it at the software level, and I came across a problem connecting to the computer, so I changed the type C connector and did all possible procedures, even using custom rom, but nothing worked.

I soon thought that it could only be the battery, given the fact that it came back from the reboot with about 10 to 20% less. But I just got the new battery and the problem continues...

I even tried to leave the side buttons disconnected, to see if the power, was not having some kind of short. But he restarted the same way.

I don't know what to try or think about it anymore, I didn't just want to leave it aside as a "Handboard or serial problem", I wanted to try everything and learn from it... That's why I want to hear your experience with this type problem, whether with this model or another.

I apologize for my English, and if I posted this in the wrong place, I'm new here.

And thank you in advance for everyone's help, and for the existence of this community as a whole!

 

[werty]

Hello everybody. I'm having a very annoying problem with this smartphone for a while.

Smartphone: Xiaomi MI 9 SE (grus)

Initially it was restarting a few times, when it was in standby, after some time it started to restart and when it came back it had less battery than before.
So even though I thought it wouldn't work, I tried to solve it at the software level, and I came across a problem connecting to the computer, so I changed the type C connector and did all possible procedures, even using custom rom, but nothing worked.

I soon thought that it could only be the battery, given the fact that it came back from the reboot with about 10 to 20% less. But I just got the new battery and the problem continues...

I even tried to leave the side buttons disconnected, to see if the power, was not having some kind of short. But he restarted the same way.

I don't know what to try or think about it anymore, I didn't just want to leave it aside as a "Handboard or serial problem", I wanted to try everything and learn from it... That's why I want to hear your experience with this type problem, whether with this model or another.

I apologize for my English, and if I posted this in the wrong place, I'm new here.

And thank you in advance for everyone's help, and for the existence of this community as a whole!

This is a forum for xiaomi.eu rom based on china rom. But you should try to flash latest fastboot rom with MiFlash - search google for guides.
Note: Choose Clean all and not Clean all and lock in lower right corner of MiFlash.
Good luck, werty

 

[gustavofalcao1]

.

 

[gustavofalcao1]

This is a forum for xiaomi.eu rom based on china rom. But you should try to flash latest fastboot rom with MiFlash - search google for guides.
Note: Choose Clean all and not Clean all and lock in lower right corner of MiFlash.
Good luck, werty

OK. I've always used the ROMs here, and that's why I asked the question here. I tried to do as you said but it didn't work, I'm totally lost, I don't know what could be causing this and I can't find anything on the internet.
I'm considering running a Linux system and see if the problem persists, I don't know what else to try and I practically gave up the smartphone as lost, I just want to find out what caused it out of curiosity and knowledge.

So if anyone has any more tips, please I'm trying anything.

 

[werty]

OK. I've always used the ROMs here, and that's why I asked the question here. I tried to do as you said but it didn't work, I'm totally lost, I don't know what could be causing this and I can't find anything on the internet.
I'm considering running a Linux system and see if the problem persists, I don't know what else to try and I practically gave up the smartphone as lost, I just want to find out what caused it out of curiosity and knowledge.

So if anyone has any more tips, please I'm trying anything.

What do you mean by didn't work. You couldn't be able to flash the fastboot rom or the issue persists after you flash it?

 

[ruvlad]

I have the same issue here.
Xiaomi MI 9 SE (grus) + Xiaomi.EU Stable 12.5 (xiaomi.eu_multi_MI9SE_V12.5.4.0.RFBCNXM_v12-11).
Clean installation with all the pre-steps. I have not modified the system partition or installed Magisk modules. I don't use AOD or special battery saving modes.
I noticed that there are fewer reboots if I use a third-party "Caffeine - Keep Screen On" app that doesn't allow the screen to turn off.
Perhaps random reboots are happening due to the work of the governor or a kernel bug, but I can't confirm it, I just assumed.

 

[NigelB]

Hi All, I am a new member from Wellington New Zealand.
I have the same problem with my Mi9SE with MIUI Global Version 12.5.1 Stable (12.5.1.0 RFBEUXM).
I think it started rebooting around July 2021. I have not fiddled with any Flash software, so it is as I imported it from China on Ebay.
The rebooting goes thru phases where it will reboot maybe up to 10 times a day, or none at all.
What also happens sometimes is that the phone becomes "bricked" and will not switch on at all - only solution is to physically disconnect the battery - this happens every other week, and always at the worst times which means I need to carry a set of tools with me (!)
Changing the battery had no effect.
Yesterday I reset the phone for the second time and did not set up anything on it - it's not even connected to wifi, no gmail account, nothing installed. It lasted 14 hrs and then rebooted by itself.
So I think Xiaomi screwed up the software running on this phone. It's a great phone but they messed it up with their MIUI software updates and I wasted my money.
We have 5 other Xiaomi phones in our household, but I don't think I will buy Xiaomi again.
If anyone has any ideas on how to fix, would love to hear from you, thx!

 

[NigelB]

Just an update on this....
I did not know anything about installing custom recovery software and ROM's, but being a software developer I managed to learn how to do this from beginner-friendly sites like https://www.getdroidtips.com.
So after installing TWRP I managed to install lineageOS and guess what? The phone kept rebooting.
Turns out that the actual problem was caused by a faulty motherboard - possibly something to do with the charging circuit.
After replacing the motherboard (which came with original MIUI software), everything is working perfectly now.
So apologies to MIUI software - it was the Xiaomi hardware that was at fault.
Hope this helps anyone else who might have the same problem.
Cheers