Cellular radio power permanently off

[HelpWithXperia]

I have an Xperia X Compact, about a year and a half old, running Android 7.0, software 34.2.A.2.47 AND 34.2.A.2.69 (problem persists in both versions. I'm about to try the newer 34.3.A.0.194 but I doubt it will help).

A couple of days ago I started to notice that 4G/LTE wasn't working very well. Trying to access sites on Chrome rendered a DNS resolution error and it only worked after turning airplane mode on and off.

Several hours later the whole cellular function of the phone suddenly stopped working (calls, SMS, 4G). At times it read that there was no SIM inserted (though there was one), but most of the time it stated that there was zero bars (empty triangle). 

Whenever I boot it now it will read "no SIM" for a long time until it gets to zero bars.

I got a new SIM card but it's still happening.

I looked into this and I found out about the #*#*4636*#*#  and *#*#7378423#*#* menus , as well as some other users with the same issue which they haven't been able to solve.
Checking that out it says that signal is -1dBm and 99 ASU. 

Full readout is below.

It shows the cellular radio power as turned off every single time. If I turn it on, leave, and go back to the menu, it's off again. It's constantly getting turned off, automatically.

So it would seem the cellular radio is not working, I cannot get it to stay on, and that's why I don't have a signal.
At the same time, since for some periods of time it isn't recognizing the SIM card, it could be that the card reader has become faulty out of the blue. 

Or perhaps the baseband chip isn't working. 

I do drop my phone quite a bit but there were no big drops the day this started happening.
I don't know if it's a hardware or a software issue.

I tried changing the preferred network type between global, LTE, GSM, WCDMA, Unknown, etc. but those choices don't stick and it doesn't help. I messed around with several of those settings to no avail.

I've tried updating the software but not the software repair so far because I want to delay that as much as possible while I diagnose the issue. 

Same goes for taking it to a service shop.

Any ideas?

F5321

34.2.A.2.69

Android 7.0

Phone number: unknown
Current network:
Signal strength: -1 dBm 99 asu
Voice service: Radio off
Data service: Disconnected
Voice Network Type: unknown
Data Network Type: unknown
Voice Call Status: idle
Roaming: not roaming

Set preferred network type: LTE/UMTS auto (PRL) [I've tried setting it to other options, doesn't help. Always reverts to that default]
Ping tests for IPv4 and IP v6: Fail(2)
HTTP Client test: Fail: IOException

Data Connection Real-Time info:
Message waiting: false
Call redirect: false
Data Sent: 0 pkts, 0 bytes
Data received: 0 pkts, 0 bytes
Number of PPP reset since boot:

Cellular Radio Power toggle: is off every time I access this diagnostic. Turning it on does not change the above info, and it turns off as soon as I leave.
VoLTE provisioned: off [turning it on doesn't help]
SMSC: blank
TOGGLE DNS CHECK 0.0.0.0 allowed [changing this doesn't help]

Cell Info Refresh rate:
Disabled [starts this way every time I access it, changing it doesn't stick and doesn't change the above or below info]
Cell Location info: unknown
Neighbor cell info: no neighboring cells
All cell measurement info:

[pseudonym]

You were certainly very thorough in your analysis of the problem. I would have suggested checking the preferred network type, but I see you've done just about everything. I also had an X Compact that would not recognize its SIM, as have others posting here. I had to return it, but am pretty sure it was a hardware failure. The fact that you mention the phone being dropped a number of times suggests that might be a reasonable posssibility for you as well. You might also post your question to the XDA forum. Good luck!

[Strampke]

Yes @HelpWithXperia you certainly have put a lot of effort in it.

I missed you trying to reset Mobile Data settings

Maybe you did and I overlooked it.

Nevertheless

reset and then download mobile data settings

And.... what happens in safe mode.

Please report back how it goes.

Maybe we can find a solution. Who knows.

[ibreakthings]

I am seeing the same problems right now with my xz2 compact. one more step that i have done is a factory reset of the phone, which seems to bring back service. This has led me to resetting my phone often since i have been unable to return my phone because of other life priorities. I actually had a long period of time(3days) where it maintained connection. But I was awake and actively using my phone for 53 hours over those 3 days. Crazy times ended and i was finally able to sleep last night. Woke this morning and connection was dead, which is now prompting me to factory reset. 

I am guessing that the phone is not pinging the network often enough if not being used, and eventually gets dropped off the network. It also appears that it is not trying to reregister if it is dropped. Factory resetting appears to force a registration, because it assumes a new phone hasn't already been registered. 

I don't know how to fix this permanently, but i at least have a short term and painful work around

[CyberMunky]

hey guys, don't know if anyone  is still following this thread but there's a fix for your problem 😀

Download your firmware with flash tool, now flash only the modem.sin files, problem solved