poco m3 does not turn on anymore

[Sus_i]

So it can be the antenne if Wifi and 2G works but no 4G? But how it can find 4G network (see screenshot)?

I get my M3 back (warranty case) and anything works but no 4G. I also try to set it LTE only with *#*#4636#*#* but than no signal at all.

If the small antenna cable is plugged in at the board, 4G should work too.

Since the phone shows on your Picture Tcom, O2 and vodafone 4G network, it's most likely an issue with your provider and/or the mobile settings...

 

[Linuxkek]

If the small antenna cable is plugged in at the board, 4G should work too.

Since the phone shows on your Picture Tcom, O2 and vodafone 4G network, it's most likely an issue with your provider and/or the mobile settings...

That is my question. Without 3G/4G antenne I should not be able to find 4G network?

I put the sim card in a other phone and get 4G. Also switch sim slot 1 and 2.

 

[Sus_i]

That is my question. Without 3G/4G antenne I should not be able to find 4G network?

I put the sim card in a other phone and get 4G. Also switch sim slot 1 and 2.

Idk. Maybe @sarabbafrani can tell us the answer.
If you want to try it, the backcover and the antenna plug is easy to remove.

 

[b1.b0r4]

I encountered this same problem, what I did was unplug the battery but still the phone won't turn on, so I drained the motherboard by placing the multi tester point on those 2 contact point just above the battery connector on the mainboard, wait till it is fully drained, 0.001v
this made it turn on after placing back the battery.

seems like a caps or power IC issue
another issue was earphone sensor

 

[n53r10us]

i dont have a heat gun.
can i remove the shield with a soldering station?

 

[Sus_i]

i dont have a heat gun.
can i remove the shield with a soldering station?

Why not? Isn't a soldering station even better than a crappy heat-gun?

 

[n53r10us]

Why not? Isn't a soldering station even better than a crappy heat-gun?

How long do i need to heat up the shield?
I stay Like the Pictures for over 10 minutes and the shield doesnt even moved a bit.

I slide the soldering slowly up and down.
So i need the bottom boarders to heat up or would it be enough to do the picture way just longer?

In the videos it looks like u doesnt even need to pressure the shield to remove.


Edit: would it be better to cover the other parts and use a hairdryer? Would this work? Or is a hairdryer not hot enough?

What do i even melting? Some kind of glue or the shield itself?


Do i need the paste they all use?could i use some pc cpu heat flow paste?

 

[Sus_i]

How long do i need to heat up the shield?
I stay Like the Pictures for over 10 minutes and the shield doesnt even moved a bit.

I slide the soldering slowly up and down.
So i need the bottom boarders to heat up or would it be enough to do the picture way just longer?

In the videos it looks like u doesnt even need to pressure the shield to remove.


Edit: would it be better to cover the other parts and use a hairdryer? Would this work? Or is a hairdryer not hot enough?

What do i even melting? Some kind of glue or the shield itself?


Do i need the paste they all use?could i use some pc cpu heat flow paste?

The shield is soldered to the board using lead-free solder, which starts melting at about 220°C.
Add some solder to the tip and use some flux too, better for heat transfer.

It may be that your soldering iron is to weak, you can try the hairdryer together with the soldering iron. Make sure to cover all parts around from airflow...

 

[sarabbafrani]

The shield is soldered to the board using lead-free solder, which starts melting at about 220°C.
Add some solder to the tip and use some flux too, better for heat transfer.

It may be that your soldering iron is to weak, you can try the hairdryer together with the soldering iron. Make sure to cover all parts around from airflow...

I use 400°C with 120 air flow quickly
Because with low temperature
Pcb transfer heat to other components on motherboard and whole of pcb gets hot. Anyway this process depends on tools and experience

 

[Aicene]

I use 400°C with 120 air flow quickly
Because with low temperature
Pcb transfer heat to other components on motherboard and whole of pcb gets hot. Anyway this process depends on tools and experience

Hello sarabbafrani ;-) Your method to wake up M3 are just excellent, but it didn't work in my case :-/ Everything starts when I want to switch from WiFi to 4G. I realize that flashlight are greyed out. Hmzz, may be problem with camera. I run it, at first sight it works, but show some error message. OK, **** happens Because I must to drive to work, I run Waze. Same situation, error message. OK, I restart it, it help me a lot of times, but not this time :-/ Just later I realize, phone are dead and found that is very common problem with M3. At that moment it at least appears on PC as Qualcomm. OK, I removed that cover(I used hot air gun), but it didn't help. What was strange, there appears like burned hole on that big grey part under that cover. After that it stops appear on system :-( Next move, I disconnect battery, plug in USB-C, then appears empty battery sign. When I push power button, connect battery, disconnect charger, it starts dead boot loop, just screen flashes without any image. I tried to find solution, but wasn't lucky still :-/
P.S. Start to think, may be I should drain the battery???

 

[Warbaby77]

Hello guys, my poco m3 died at 100% battery charged. How can I drain my battery faster, anyone? Thanks.
Note: I've tried holding the power button, nothing yet.

 

[Pablo Sub-Zero]

Guys my battery is still not drained, its 3 weeks now

 

[Sleltry]

I found this post about 2 months ago and try to disconnect the battery to try turn on like was mentioned, so I bought some precision tools and open the phone, finally I could turn on. But after 1 month it was slow and I needed to restart, and this time I couldn't turn on again. So I went to a repair shop and ask the guy to only remove the shield. After the board cool down, I placed all back and the phone turn on normally. Don't have any problem with 4g yet.

Thanks to @sarabbafrani and everyone who tested and posted

 

[Elijahfrodo]

I use 400°C with 120 air flow quickly
Because with low temperature
Pcb transfer heat to other components on motherboard and whole of pcb gets hot. Anyway this process depends on tools and experience

Good morning from Nigeria. My Poco M3 came back to life after removing that cap you said we should remove. Theses no issue with it and I've been using it for the rest four days now. Thank you sir

 

[ogy_j]

Yes i've order a new one, but without this, the phone won't show battery sign on the LCD..
I hope this is it otherwise there is something wrong on the motherboard

I've install the new button but the phone still don't want to start
The shield has already been remove

The screen show no battery, i'm charging like 25% then try to power on but i've got a black screen then i've to wait the phone discharge

I've also reassemble back the phone but still doing the same

 

[zaki789]

It did work by removing the shield but now i have a new problem network on both sim card is not working it only works when switch to 2g only i need some help please

 

[sukinsyn]

I encountered this same problem, what I did was unplug the battery but still the phone won't turn on, so I drained the motherboard by placing the multi tester point on those 2 contact point just above the battery connector on the mainboard, wait till it is fully drained, 0.001v
this made it turn on after placing back the battery.

seems like a caps or power IC issue
another issue was earphone sensor

Thank you for your advise with using multi-meter to dr! It worked for me. You are my saver!
Also I'm curious if you just short those 2 contacts for power drain(if people don't have multi-meter), would it be fine, would it provide the same effect?

 

[ogy_j]

Can you do a picture of that plz ?

 

[Sus_i]

It did work by removing the shield but now i have a new problem network on both sim card is not working it only works when switch to 2g only i need some help please

Make sure that the small antenna cable is plugged in at the board...

 

[zaki789]

Make sure that the small antenna cable is plugged in at the board...

Well I broke the original cable now i replace it from a repair shop they told me it's from a poco m3 but still the same problem only gsm and 2g works no 3g/4g