Sony Xperia XZ3 H9436 (Possible cell radio problem) Restarts without plane mode.

[Oldschool297]

I have a problem with my Sony Xperia XZ3 H9436 it restarts after a halv or in a minute in normal mode. Even with a sim or without. It only works without restarts in plane mode or in safe mode with plane mode. I have android 10. I have tried to turn of side sensor and one hand sensor since another had that problem. Is there any way to test the cell radio? I doubt i can use secret codes in the phone since i can't use a sim. 

[EMS_MO72]

Hi 2Oldschool297

Can you confirm if your phone acts normally and doesn't restart when it's in safe mode or airplane mode? 

I didn't get that part from your post 

[Oldschool297]

It only works in plane mode and always restarts after 1 min in both normal mode and safe mode without plane mode. And if you start it and do not touch lockscreen before the screen goes off it also restarts. But if you touch the lockscreen and have plane mode on it don't restarts, but if you don't touch the lockscreen and login after 30sec the phone restarts. Even if plane mode is on. It works fine in plane mode but you must login before the screen goes off. If you have login to the phone and have the plane mode on and get to lockscreen it works fine. 

Every function works fine in plane mode and wifi. But as you know you can't use sim in plane mode and i guess it is the problem. I think the cause is the thing (Cell radio?) that handles signals to the card as it works in plane mode. I have tried all functions under xperia tests but for gps it  hangs and restarts. I guess it needs a sim or it was a temp fault. 

[HannahEd01]

Hey Oldschool297, did you try a software repair? https://www.sony.co.uk/electronics/support/mobile-phones-tablets-mobile-phones/xperia-1-iii/articles... 

[Oldschool297]

I couldn't install the Xperia Companion on Windows 7. I need for X86. It only showed up wrong for my computer. I have figured out it is the sim card when it work in plane mode with wifi, it can restart when locations for weather is turned on or when you try the gps in Xperia test. Someone tip me on the battery. I find the sim in normal mode but it restarts soon after so i can't check long. It is a little more complicated to remove batteri in this phone as the motherboard, camera and more things must be removed, in my Sony Xperia Xa F3111 it is only a piece of tape that has to be removed. Someone told me it could be the battery that can't give enough power to the radios handling signals to sim or gps. Shouldn't it take more voltage to stream and record video in 1080p or play games? I can stream video in 1080p and record to. I gave a try when the battery was on 78% after 40min it was on 66%. But it may give wrong voltage for radios and gps. 

[Oldschool297]

I did try a software reset in my phone options but the phone restarts before it gets completely done. But i got it to work with plane mode. But it always restart in normal mode. 

[HannahEd01]

Hey Oldschool297, I recommend you send to for repair, I believe you can book it from here: https://sony.sbe-ltd.co.uk/callcenter/booking 
 If you're based in the UK

[HannahEd01]

@Oldschool297, by the way, the factory reset isn't the same as the software repair. The second one is better as it resolves software glitches. 

[Segundo37]

I had the same problem, reboots and lack of coverage, there were times when it was reboot after reboot for hours, although there was no pattern like yours, I formatted it to factory mode but everything was the same, do you know how I recovered it? hitting it with a flat hand on the screen, with energy, I have been with it for 4 years and I felt that it was not going to fix it, so I tried violence, it worked without problems for 4 days, then it failed again and I used the same technique, now I've had 0 problems for 7 days, something was moved in there and it was repositioned, but hit it with energy and with a flat hand so as not to cause breakage, on the screen, Excuse my translator's English, greetings.

[SkyNet404]

Are you sure that using violence with electronics is the best solution? 
Especially if it's a phone with a big beefy battery? I wouldn't recommend that mate 😅.