Database Develop

Loosing network signal

Hi!
After weeks of flawless function my Xperia can not find my carriers phone network.
I have updated the phone to the new ROM but that does not help.
The phone finds the SIM card and asks for the code.
Strangly it can connect to internet through my carrier (Tele2).
But I can not get a connection to the phone network and make a normal phone call.
Is something wrong with the phone?
NO, cause with another carrier (Telenor) everything works pefect.
Then obviously something is wrong with my carrier (Tele2) or the SIM-card.
NO, cause when I put my Tele2 SIM-card in another device (Ipaq 6515) it works perfect.
The Ipaq is not a 3G-phone. Can that have anything to do with it?
I'm getting lost here, all help is appreciated.
(ORIGINAL MESSAGE
Hi!
After weeks of flawless function my Xperia has started to lose it's phone network.
I notice it after I wake my phone up from stand by mode.
It doesn't help to turn the phone option off and on in Comm manager, but it has sometimes helped turning flight mode on and off.
Other times I had to restart the phone.
This happens a couple of times every day, after long times of not using the phone. I have not been able to trigger this problem, so I don't know what causes it or exactly when it happens.
Strangly it can connect to HDSPA while it has lost the phone network.
I have also experienced som freezes when I'm flipping between the panels to much.
All help is appreciated, thanks.

It would be helpful if you could give us more information.
What ROM are you using
Which carrier you have
etc.

mo.ammi said:
It would be helpful if you could give us more information.
What ROM are you using
Which carrier you have
etc.
Click to expand...
Click to collapse
I'm using:
ROM 1.02.936.3
Radioversion 1.06.25.29
The carrier is Swedish Tele2.
In Sweden we have GSM-900 and GSM-1800.
Tele2 also provide me with UMTS and HSDPA.

Today the problem became worse.
Even after repeated soft restarts it refused to find the phone network.
Then I change SIM-card to another carrier and it found the network.
I also tried the SIM-card that's giving me problems in another device. Works fine.
So both SIM-cards works. I'm now gonna go with the new carrier during the day to see if the problem come back.
If anyone have any ideas, please help.

krion said:
Today the problem became worse.
Even after repeated soft restarts it refused to find the phone network.
Then I change SIM-card to another carrier and it found the network.
I also tried the SIM-card that's giving me problems in another device. Works fine.
So both SIM-cards works. I'm now gonna go with the new carrier during the day to see if the problem come back.
If anyone have any ideas, please help.
Click to expand...
Click to collapse
All I can say that Xperia sometimes looks for the signal a bit longer it should IMO,
but I also know that carriers have many many problems usually and they're also often responsible for signal drops in some places too.
I know that 'cos I was talking to my carrier many times about it and learned something about it...

have u tried hard resetting the phone or re-installing the software? ..
if u run the sony update software it will give u the option to re-install your phones software - not sure if that has the same effect as a hard reset ..
probably worth trying

Amanox said:
have u tried hard resetting the phone or re-installing the software? ..
if u run the sony update software it will give u the option to re-install your phones software - not sure if that has the same effect as a hard reset ..
probably worth trying
Click to expand...
Click to collapse
Thanks for answering, I have now done a total reinstall and updated the phone to the newest R2... ROM.
The problem remains.
The phone finds the SIM card and asks for the code.
It can connect to internet through my carrier (Tele2).
But I can not get a connection to the phone network and make a normal phone call.
Is something wrong with the phone?
NO, cause with another carrier (Telenor) everything works pefect.
Then obviously something is wrong with my carrier (Tele2) or the SIM-card.
NO, cause when I put my Tele2 SIM-card in another device (Ipaq 6515) it works perfect.
I'm getting lost here, more ideas is appreciated. Tomorrow I will call Tele2 support.

Have you tried disabling 3G/HSDPA?
Chance that you have very poor 3G on your phone, whilst the IPAC is picking up ok 2G.

artesea said:
Have you tried disabling 3G/HSDPA?
Chance that you have very poor 3G on your phone, whilst the IPAC is picking up ok 2G.
Click to expand...
Click to collapse
Thanks for replying.
I disabled HSDPA/HSUPA in the advanced network menu. But it didn't help.
I also tried to choose GSM only in the phone seetings menue. But I could not even change the setting. Just got an error message about not being able to change the network (or something similar).
Is there any other setting that might be worth trying?

krion said:
Thanks for replying.
I disabled HSDPA/HSUPA in the advanced network menu. But it didn't help.
I also tried to choose GSM only in the phone seetings menue. But I could not even change the setting. Just got an error message about not being able to change the network (or something similar).
Is there any other setting that might be worth trying?
Click to expand...
Click to collapse
Having worked for several phone companies a few years at customer service I know what the procedure is.
-First thing they do is ask you to do a "crosstest", try your SIM in another phone and see if that works.
-You'll tell them that you did that and everything works fine when you use another phone.
-They'll automatically conclude that there's something wrong with your phone (correctly)
-They'll ask you if you could do a hard reset ( You did that too)
-Then maybe they'll try and reset the network (which almost never works)
Basically they'll have no other choice then for you to return it and have them look at the problem / replace your phone.
I don't think we here can help you with your problem
Good luck and keep us posted

Get a new SIM card. I've seen problems like this before, and an updated SIM card solved it.
The best way would be to test your SIM card in a similar phone, the ipaq not being close because it's not even 3G.

maedox said:
Get a new SIM card. I've seen problems like this before, and an updated SIM card solved it.
The best way would be to test your SIM card in a similar phone, the ipaq not being close because it's not even 3G.
Click to expand...
Click to collapse
I'm so confused right now.
Got my new sim card today, problem remains.
I call the carrier support and after they've looked the IMEI-number up they say that the phone is barred by an external operator. They won't tell me the reason and by what operator.
So I call the other carriers support and after they've done a IMEI-search they say that the phone is not locked in any way, by them or any other operator. After have been talking to Xperia support they come to the same conclusion. The phone is not locked but agree to that something is wrong, with phone or carriers, and they want me to try with a third carrier.

Final
I've handed in my phone to the seller and got another one back instead.
The end

Exact same problem
Howdy folks,
I have the exact same problem: My Xperia has worked fine for a month. Suddenly I can't register with Tele2 network (tried another Tele2 card as well that didn't work) for calling but have access to data channel so I can surf. Got told by the Tele2 support that my phone was fu**ed up. Got pissed off. Tried a sim for another provider (Telenor) that worked. Called the Tele2 support again. They noticed that I have an old (2g) sim, so they will send a new (3g) card to test if that fixes this mess. It should arrive late this week or early the next. Can't wait...
I'll keep you posted in this thread (or, if I should instead have made a new thread, a moderator may spank me and I will do better).
/Swedish Dave

Nope, new sim-card didn't fix it. But I have found at least one other xperia-user with this problem...

bad GSM signal
I have a X1
rom 1.03.931.10
radio 1.10.25.18
protocol version 52.56.25.29W
and since from the start I have bad GSM signal I have like 1-2 lines onli and it go up to 5line but onli from time to time (and then it drops again to 1-2line or none but If Itray to call is working or I get called but I can berly hear them bicose of the bad signal) on O2 network and in T-mobile is the same no mather wher I'm in town or outside of town; I'm in UK
is the phone damaged?? or...
sry for my bad english

My phone does the same thing
My x1 has had no problem with phone function or network. However, from the last week, the signal began to be lost sometimes, and the machine turned off automatically. and finally today, there is no signal at all.
MY SIM card works with other phones, so, I thought it might be software problem, and hard reseted with new rom. However, still no signal. It keeps looking. Does anyone have the same problem, and hopefully, solution?

I´m using my X1i with Tele2 as my service provider,but i don´t have any problems with signalstrength.. Works just fine..

speederTM said:
I have a X1
rom 1.03.931.10
radio 1.10.25.18
protocol version 52.56.25.29W
and since from the start I have bad GSM signal I have like 1-2 lines onli and it go up to 5line but onli from time to time (and then it drops again to 1-2line or none but If Itray to call is working or I get called but I can berly hear them bicose of the bad signal) on O2 network and in T-mobile is the same no mather wher I'm in town or outside of town; I'm in UK
is the phone damaged?? or...
sry for my bad english
Click to expand...
Click to collapse
I know I should've introdouced myself first, and that this is a strange first post, but:
HOLY SMOKES!!!
Xperia has FIVE reception bars????!!!!!
I always thought that 3 is the max value, since it only happened once that it went up to three bars, rest of the time it's maximum 2, usually 1.
I am also on Tele2 carrier, in Sweden that is, and since yesterday, I have no reception AT ALL.
Nothing.
Tried turning off 3G(or whatever it's called), nothing happens.
Tested with 3 other cards (one Tele2, one Telenor, one Telia) - all seem to be working okay. Except that the Tele2 one has slightly lower reception than the others.
Tested with 3 other phones as well - iPhone 3GS, Nokia 5800 Xpress Music, HTC Desire. All of them worked perfectly. Full coverage on that super-fast network thingy(the 3G symbol on iPhone).
Internet is just flowing on other phones - but Xperia is just falling behind in the most important section - reception.
Calls get dropped (2/3 of the calls), I must send same message at least 3 times in order to get it sent, Internet is crappy - if there's any at all.
Any kind of guidance is mostly appreciated.
P.S. A bit of those numbers which seem to be important:
Microsoft Windows MobileR 6.1 Professional
CE-OS 5.2.19608 (Build 19608.1.2.60)
ROM-version: 1.05.936.9
ROM-date: 04/19/09
Radioversion: 1.14.25.55
Protocol version: 1.0.11842.32680

Since all of you seem to have problems with one and the same carrier (Tele2) why don't you simply switch to another one? I once had a problem that was very alike the one described here and after several unsuccessful attempts of the carrier to fix it I simply switched to another one and all my problems were gone.

[Q] Can't set APN, and other SIM problems

Hello,
I have problem with SIM card on my phone. I'm using Temasek's CM 10.1, Kowalski kernel, and V20I-EUR-XX baseband. When phone boots, I normally input my PIN, but it doesn't connect to network, I have to go to Mobile networks and Choose operator automatically, then it connects. I can call and send messages normally, but when the call hangs (me or the other side) it says SIM card error (something like that). Also I can't save APN. In APN settings there is nothing, and when I create APN manually, I input everything and press save, but it doesn't stay, APN's remain empty. I use micro-SIM with adapter, because my operator couldn't get me normal SIM at a time. I'm on Croatian provider VIP. Everything normally worked with micro-SIM from Tele-2 provider (although on CM 10, and CM 7, didn't test it on CM 10.1).
Is it related to my SIM card or SW (ROM or baseband)?

mind_challenge said:
Hello,
I have problem with SIM card on my phone. I'm using Temasek's CM 10.1, Kowalski kernel, and V20I-EUR-XX baseband. When phone boots, I normally input my PIN, but it doesn't connect to network, I have to go to Mobile networks and Choose operator automatically, then it connects. I can call and send messages normally, but when the call hangs (me or the other side) it says SIM card error (something like that). Also I can't save APN. In APN settings there is nothing, and when I create APN manually, I input everything and press save, but it doesn't stay, APN's remain empty. I use micro-SIM with adapter, because my operator couldn't get me normal SIM at a time. I'm on Croatian provider VIP. Everything normally worked with micro-SIM from Tele-2 provider (although on CM 10, and CM 7, didn't test it on CM 10.1).
Is it related to my SIM card or SW (ROM or baseband)?
Click to expand...
Click to collapse
Not sure if you read my post, but I think we are having the same issue regarding the APN, etc.
Not been able to solve mine yet, perhaps together we can put out enough info that someone here can offer a solution? I haven't changed the baseband or kernel on their own, only went from stock 2.3.3, to CM10.1, then to CM7.2.
Are you able to remove the SIM PIN? If you remove the SIM PIN from security, are you able to save APN?
Does your phone access data with the native SIM card the phone was originally locked to?

gglobal19 said:
Not sure if you read my post, but I think we are having the same issue regarding the APN, etc.
Not been able to solve mine yet, perhaps together we can put out enough info that someone here can offer a solution? I haven't changed the baseband or kernel on their own, only went from stock 2.3.3, to CM10.1, then to CM7.2.
Are you able to remove the SIM PIN? If you remove the SIM PIN from security, are you able to save APN?
Does your phone access data with the native SIM card the phone was originally locked to?
Click to expand...
Click to collapse
It seems that PIN is already disabled in Settings-Security-SIM card lock settings :silly:
I called my old operator and they told me my phone was sold locked, and new operator told me they can't help because I didn't buy the phone from them. But then how it works now for calls and messages?
I don't have any other SIM with me so I can't test it with my phone. You say going back to CM7 didn't help? I guess I shouldn't try that then.
Maybe flashing stock ICS would? Any other suggestions?

mind_challenge said:
It seems that PIN is already disabled in Settings-Security-SIM card lock settings :silly:
I called my old operator and they told me my phone was sold locked, and new operator told me they can't help because I didn't buy the phone from them. But then how it works now for calls and messages?
I don't have any other SIM with me so I can't test it with my phone. You say going back to CM7 didn't help? I guess I shouldn't try that then.
Maybe flashing stock ICS would? Any other suggestions?
Click to expand...
Click to collapse
I haven't tried stock ICS yet; maybe it would? I will try that tonight.
Mine shows the SIM PIN on, when I try to change it it asks for my old code, which I don't have of course, so I can't remove the security. Been hoping that someone else would have had experience or knowledge of what would cause the problem and have a solution or suggestion to try. The closest I came was on a different forum about a Sony Ericsson phone, but the rooting and flashing procedures are so much different I couldn't see a solution in it, though they suggested flashing the baseband iirc.
HMMMM, now that I read your reply, I can't say with 100% certainty that the phone was unlocked before I rooted and flashed CM10.1.....I had thought it was but perhaps it wasn't, and we are having a more similar issue than I thought. So the glitch, perhaps, is that it was not unlocked, the custom ROM somehow "half" unlocked it, and here we are stuck.
Okay, my only thought then is to take it back to stock everything, the most up to date I can find, then unlock it with code, and see if I can change the APN at that point. If so, I will root it, use My Back Up Root to save settings including APN (just in case so at least I can restore it that way if I can't do it manually, after)flash CM10.1 again or another fabulous custom ROM which is what I really wanted in the first place
I will try that tonight, and post you the results. Let me know if you have any (better) suggestions as well, I'm up to try almost anything at this point. Was hoping to upgrade to this for my daily phone as I'm limping along with a Acer Liquid MT that has seen better days
If anyone has a link to quickly point me towards the latest stock ROM etc. and wants to post here, I would be much obliged Might save this noob a few hours scratching his head to find what is most certainly in front of my nose already, but I digress...
Cheers

New baseband
I just flashed V30A baseband, and it didn't help. We can cross that from the list.

Well colour me confused...and happy?
I just today picked this project up again, about to attempt a different fix, again...*sigh.
Lo and behold, i insert my sim and power on the phone, and it asks me for network sim unlock.....odd because I'd used the phone with this sim before, through all my other testing, flashed different roms, etc. etc. In fact, I've used the phone on this very package, I know because there are sms messages on the phone from using it. Battery pull, remove sim and check, yup sure enough, old messages there. Hmmm...
Insert sim, reboot, asks for unlock code again. Well, what have I got to lose at this point right? As I said before, I THOUGHT I had unlocked the phone before starting this whole debacle, but wasn't 100% certain about it. Searched my email for the code since I always save them, couldn't find it. Well, in for a penny, in for a pound I suppose. Bought a new unlock code, waited for it to arrive. Input new unlock code, unlock successful!!
Reboot phone....waiting for service....(this seems like forever!!! In reality, less that 60 seconds.) Alas, I have service. And now, just to tempt fate, Apps->settings->wireless & networks->more->mobile networks->access point names..........:fingers-crossed:
I can hardly believe my eyes, there it be, Rogers Internet apn selected. It even auto-detected the damn thing!!
I can offer no further insight, I don't believe I physically did anything to arrive at this remedy. But there you go, for my part at least it's solved.

Mi 9 - Android Q Mobile Network isn't available

Hi,
I just bought a Mi 9 for my gf as Birthday gift and have a big problem with it.
We use her Simcard from her further phone, which works there without issues, but the Mi 9 just let her use Data on the simcard (internet). No calls or texts in-/ outbound are possible. It always shows that no mobile network is available.
I already readded all APNs (Internet, LTE, GPRS) and tried a couple different network settings (*#*#4636#*#*). I'm not sure why this issue appears and searched allover the internet. Seems like noone else have this problem.
Version is 11.0.2.0(QFAMIXM) with locked bootloader. Could it be that seller flashed something wrong, modem type or whatever? Carrier lock wouldn't let us use the actual sim right? My own sim as well just work with data so it need to be an issue with the phone.
Thanks in advance
Chris

Noone have any idea what the issue could be?

This seems like an operator related issue and probably has nothing to do with the Mi9. Try operator related forums for more help. The only thing that comes to mind is to get a new sim from the operator.

ChrisMNL said:
Noone have any idea what the issue could be?
Click to expand...
Click to collapse
Question:
Does mi9 recognize the SIM Card? Does mi9 ASK for your SIM Card PIN? Or does mi9 say 'no SIM Card installed'?

Hi,
Sim is recognized and contacts shown. Sim pin is deactivated so the Phone don't ask.
Mobile Network is shown and active and data/ internet works. Its just the GPRS funtions (Text, Calls) which don't work. When I try to call I get the "Mobile Network isn't available" message and texts don't sent.
Thanks

This seems like an operator related issue and probably has nothing to do with the Mi9. Try operator related forums for more help. The only thing that comes to mind is to get a new sim from the operator.
Click to expand...
Click to collapse
The Sim works fine in another phone and my sim which works as well, shows the same errors in the Mi 9. So it must be an phone issue.

ChrisMNL said:
The Sim works fine in another phone and my sim which works as well, shows the same errors in the Mi 9. So it must be an phone issue.
Click to expand...
Click to collapse
What operator do you use? What operators are the respective cards you have tried in the Mi9? Did you buy the phone from a private person and not new in a sealed package? In this case contact the seller.

ChrisMNL said:
The Sim works fine in another phone and my sim which works as well, shows the same errors in the Mi 9. So it must be an phone issue.
Click to expand...
Click to collapse
Do you have 2 simcards installed?
You also might try to reset the modems, howto you can find when searching the forum

Just 1 sim installed. 2nd slot shows the same issues. Will check the forum for modem reset thanks.

Hi,
Weirdly the phone seem to have a Carrier Lock. My gf uses SMART Prepaid here on the Philippines and as said just mobile data was working. Yesterday she switched the SIM for testing to Globe and with this SIM everything works. 4G is available and calls/ texts work as they should.
I'm still confused about this. If the Phone would be carrier locked, should another Carrier SIM not be functional at all? I don't get why Data connections are working then.
For now the solution is to get another SIM. Probably let it unlock in a store.
Regards
Chris

Question Help me fix it

Hello guys. I bought a s21 ultra 9980 512gb.
However, i cant use it with sim card as its not detecting the network. I dont get it what could be the problem. I cant even untick the automatic network search as i get error.
Will post you guys here some photos maybe you can help me out. I dont think is locked because i dont get any message when i insert sim to enter the unlock code. What could be the problem?
Please help. Thx

Are you sure its an active sim card?

Yes. I have the card in an iphone as its my current sim..

JesuisAmy said:
Yes. I have the card in an iphone as its my current sim..
Click to expand...
Click to collapse
Is the Samsung running official FW?

Yes… original .

do you still have the imei number present in the settings and if you type *#06# ?

Might be sim locked by the carrier, you could theoretically still use the esim I believe if it isn't giving you an option to enter an unlock code.

Yes.. both imei show up.
How can i check for sure its sim locked?
Also, when i insert any sim, for one second the “no signal sign” near the battery goes away then comes back instant.. and it doesnt ask for any pin…
Thanks for your inputs

I have read about this issue before as well. Is this a "dual sim" model? Try the other slot if it is, and also try leaving the sim in and rebooting. You could also try "reset network settings" under settings. I'll have a look to see if I can find the thread where people said they had a fix.

is it yours from brand new? and have you checked to see if it black listed? also, there seems to be an issue with some Samsung where they are forced into airplane mode the only way you see this is the notification panel the airplane model toggle is half-lit blue I could be something to do with that. Failing that it could also be if you have dropped the device the ribbon may have come loose as this is a common issue with Samsung a range and that's all I'm seeming to fix lately

Hello. No, didnt buy new. I got it used.Yes its dual sim model. It doesnt appear as blacklisted.
Its not in airplane mode for sure. Also i did factory reset and also wrote all stock firmware ap cm bl csc from samfirmware..but its the same as before.
Also, esim doesnt show up under the sim card manager.

try *#2263#* to change bands, or *#0011#

Maybe also try to put the sim in the other slot, and see what happens. If all the same, try someone elses SIM card for a minute to see. Maybe your sim has become slightly damaged but your iphone still manages to read it, while for some reason the s21 is not managing.

Just tried the sim in my sisters s20 and works. Also tried her sim into this new phone and same . Even if i put in sim1 or sim2.

JesuisAmy said:
Just tried the sim in my sisters s20 and works. Also tried her sim into this new phone and same . Even if i put in sim1 or sim2.
Click to expand...
Click to collapse
Sounds blacklisted to me

How can i find out if its really blacklisted or its the ribbon as galaxys2tav said?
I checked imeis and also serial number and its not blaclisted

See?

JesuisAmy said:
See?
Click to expand...
Click to collapse
Found this online:
"In Settings go to network mode and set this to 3G only. Then restart your phone. This works in my case."

Thanks for your sugestion. But its the same…

I had the same issue on single sim korean unit...but factory reset resolved the issue. Actually i used to disable carrier apps which was causing this issue.

No mobile network connection, no IMEI

Hello,
my Xiaomi Mi 9T Pro running on stock MIUI Global 12.5.1.0 (RFKEUXM) can now suddenly not connect to my mobile carrier.
I hope somebody can help me out.
Some facts and stuff I have tried:
The connectivity icon on the top is just grayed out now and shows an X.
But that was not the case in the morning today.
At that time it showed full bars, but not the usual 4G text and the mobile internet did not work. After some attempts written below it is now just gray.
Mobile internet and cell service do not work.
I have rebooted multiple times.
The IMEI for both SIM slots is shown as 0.
No baseband version is shown.
(I am sure that this was also not the case early in the morning.)
I have never installed a custom ROM on this device, bootloader was never unlocked.
The SIM card is correctly inserted and the phone number is shown in the settings for SIM slot 1.
Trying SIM slot 2 (incl. reboot) did not fix the problem.
The SIM status shows that the service is not available, also on the top left when the phone is locked. ("Dienst nicht verfügbar" in German locale.)
Trying the SIM in another phone works, which I think makes it not a carrier problem.
Trying another SIM in my phone also does not work.
I unfortunately had dropped the phone days before, but no damage visible at all (phone case FTW).
Also it worked without problems, which makes me hope this is not hardware related.
WLAN works, so internet connectivity is possible.
Phone is out of warranty.
I did search for other threads with similar issues, but they all seem to be related to having flashed custom ROMs and then losing the IMEI.
Does somebody have any idea how I can fix this?
Thank you!
Edit: I just remembered/saw that I did do the "Xiaomi Service Framework" system app update to version 6.0.6-G yesterday night, maybe that caused the problem? Currently researching on how to roll that back. If somebody knows, please do tell.

@Philipp said:
Hello,
my Xiaomi Mi 9T Pro running on stock MIUI Global 12.5.1.0 (RFKEUXM) can now suddenly not connect to my mobile carrier.
I hope somebody can help me out.
Some facts and stuff I have tried:
The connectivity icon on the top is just grayed out now and shows an X.
But that was not the case in the morning today.
At that time it showed full bars, but not the usual 4G text and the mobile internet did not work. After some attempts written below it is now just gray.
Mobile internet and cell service do not work.
I have rebooted multiple times.
The IMEI for both SIM slots is shown as 0.
No baseband version is shown.
(I am sure that this was also not the case early in the morning.)
I have never installed a custom ROM on this device, bootloader was never unlocked.
The SIM card is correctly inserted and the phone number is shown in the settings for SIM slot 1.
Trying SIM slot 2 (incl. reboot) did not fix the problem.
The SIM status shows that the service is not available, also on the top left when the phone is locked. ("Dienst nicht verfügbar" in German locale.)
Trying the SIM in another phone works, which I think makes it not a carrier problem.
Trying another SIM in my phone also does not work.
I unfortunately had dropped the phone days before, but no damage visible at all (phone case FTW).
Also it worked without problems, which makes me hope this is not hardware related.
WLAN works, so internet connectivity is possible.
Phone is out of warranty.
I did search for other threads with similar issues, but they all seem to be related to having flashed custom ROMs and then losing the IMEI.
Does somebody have any idea how I can fix this?
Thank you!
Click to expand...
Click to collapse
Did you check Settings, SIM cards and Mobile networks, SIM 1 (if SIM is in Slot 1)
Do you have Turn on? If Turned Off, then do Turn On
If not, ie if it does not recognize the SIM card, then it looks like a hardware issue
Assuming, as you say, that SIM card is ok, correctly inserted, and that phone runs only the stock firmware - hence no root, no custom ROM, no custom Recovery (that user could possibly wipe partitions), etc
Maybe, some connection got loose and later disconnected completely

Thanks for you answer.
I am sure the SIM is inserted correctly and working. It's been in there probably for years now.
Don't know if you saw my update above about "Xiaomi Service Framework". Checking that right now. Maybe I should just do a factory reset.
What I have noticed now a couple of times is that the phone crashes and reboots, just now happened when I connect for USB debugging or before when trying to enter the SIM pin after a reboot, ...

@Philipp said:
Thanks for you answer.
I am sure the SIM is inserted correctly and working. It's been in there probably for years now.
Don't know if you saw my update above about "Xiaomi Service Framework". Checking that right now. Maybe I should just do a factory reset.
What I have noticed now a couple of times is that the phone crashes and reboots, just now happened when I connect for USB debugging or before when trying to enter the SIM pin after a reboot, ...
Click to expand...
Click to collapse
But if the phone does not recognize the SIM card, it would not ask for the SIM pin

zgfg said:
But if the phone does not recognize the SIM card, it would not ask for the SIM pin
Click to expand...
Click to collapse
Agreed, therefore I am sure the SIM is recognized. The phone even shows my number and the SIM has the carrier name.

@Philipp said:
Agreed, therefore I am sure the SIM is recognized. The phone even shows my number and the SIM has the carrier name.
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If the carrier name is recognized, then IMEI cannot be NULL
Very strange
Try to play with Preferred network type setting
Maybe something really got wrong with the updated Framework

zgfg said:
If the carrier name is recognized, then IMEI cannot be NULL
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Oh, I though the IMEI is device specific and should be there even without a SIM inserted.

@Philipp said:
Oh, I though the IMEI is device specific and should be there even without a SIM inserted.
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AFAIK too - but without IMEI it could not attach to the network and therefore cannot show carrier name
Hence strange, and/or the contradictory descriptions/observations

zgfg said:
AFAIK too - but without IMEI it could not attach to the network and therefore cannot show carrier name
Hence strange, and/or the contradictory descriptions/observations
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Ohh, sry there is a misunderstanding.
The carrier name is only shown as the NAME of the SIM card (I guess it is stored on there or the phone has remembered it). But there is NO connection or carrier name shown in the top notification bar.

@Philipp said:
Ohh, sry there is a misunderstanding.
The carrier name is only shown as the NAME of the SIM card (I guess it is stored on there or the phone has remembered it). But there is NO connection or carrier name shown in the top notification bar.
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Yeah but you still have unknown IMEI - that's something that should have not happened
Anyway, go to Preferred Network Type and try with Prefer 4G, Prefer 3G or Prefer 2G - maybe, with the updated Framework, something went wrong with the bands support or so
If it wouldn't help, then I'm out of the ideas how to solve

So I did do a hard reset now, and it worked for a short time (IMEI is back), then it doesn't again, and ... just now again. It really is not stable.
Thx. I will post updates when I know more.

Unfortunately the phone keeps crashing and rebooting when using it. It just freezes and restarts, and sometimes it takes a long time to restart (seems like a crash loop).
Twice I also saw some graphic artifacts (bright magenta and green) on a small part of the screen.
I don't think this is just a mobile network connection problem anymore.
BTW: I have installed an older version of Xiaomi Service Framework (also the hard reset reverted it to a much older version), but that did not help.

Hey!!
I hope you doing great
Did you manage to solve the issue?

@Fawad Hussain
Unfortunately I could not solve it, so I am not able to use the device anymore.
Btw, as far as I can see there is no current smartphone without a notch/punch hole which is not gigantic (ASUS Rog Phone 6).

Fawad Hussain said:
Hey!!
I hope you doing great
Did you manage to solve the issue?
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Same thing happened to me, I have managed to get it thanks to this guy in the video which I don't understand what he is saying but I just followed his steps, so if you are looking for a solution this video is.

But my device is not rooted and bootloader is locked, I tried ways but don't know how to root it or unlock bootloader properly