Sim not working when i change Preferred data Service network to the same sim

Hi All,

Im using Dual Sim and I use Mobile date in Sim1 only.

Today in sim 1 there is no signal im not able to call, use mobile data etc., its like offline. i have restarted same issue then i changed the slot of my sim 1 into sim 2 then its started showing the signal status into green then when i tried to change my preferred data service network into sim2 my signal lost same issue started in sim slot 2 as well.

I have wiped the cache, restarted but still same issue
can anyone suggest me

Thanks in advance for the replies..

When Signal Loss occurs, try this

Settings >> More >> Cellular Network >> Network Operator > Search for network check whether the operator is listed.

Due to technical issues on operator's side "3G only" Mode might not work at times.
So choose "2G" or "2G / 3G / 4G" or "2G / 3G"

Check with other SIM Cards from other operators whether same issue occurs or not.

Hi Madhumathinagaraj,

If you still face the issue, we suggest you to visit the service center and get the device checked.

Here is the link

http://www.asus.com/in/support/Service-Center/India

Ok let me try and ill update..

I want update my phone software. Please help me 

chenjubabu posted on 2017/5/9 16:41
I want update my phone software. Please help me 

New firmware 540MB comes to directly to device, after checking system update.
If you want to update by manual means , download firmware 21.40.1220.2087 from asus support website for this phone.
Update via recovery mode

Enable aeroplane mode and the. DisaBle , see it's work.
There may be a problem in your SIM card or network operator. 
Check with other co users having same issue.
Go to settings - backup & restore -- network settings reset - click  ok. 
Restart the phone. And see the problems solved.
Boot the phone in safemode and recheck.
 Reply to me.