1. Android Central Question's Avatar
    Hello,

    I have a Mi A1 (up-to-date with last september security patch).

    Sometimes (almost 1 time per day), I have a total loss of mobile service, no data, no sms, no call.
    I have to reboot and then everything comes back to normal.
    Switching to airplane mode doesn't help.

    During this loss of service, I discovered that prefered network in *#*#4636#*#* menu is set to UNKNOWN.
    My sim card seems to be still recognized, but no service at all.

    I tried a factory reset without success.

    My question is:
    Is it possible that the issue comes from the SIM card ?
    How can I find the root cause ? Is there some logs that may help to find what happens?

    Thanks
    10-04-2018 02:11 PM
  2. Rukbat's Avatar
    If the SIM card can't connect to the tower (it has a number - when it tries to connect it sends that number - the carrier looks it up, recognizes it as an activated SIM, and connects you), you can't get 2G, 3G or 4G. Wifi yes, but you have to get a 2G connection (3G with AT&T) before you can get anything else.

    Bring the phone to your carrier. The SIM card is probably intermittent. No logs, unfortunately - the "unknown" carrier indication is enough to show that it's either the SIM card itself or the port it connects to. And the phone can't tell which.
    10-04-2018 04:35 PM
  3. Sigma Pic's Avatar
    The SIM card is probably intermittent. No logs, unfortunately - the "unknown" carrier indication is enough to show that it's either the SIM card itself or the port it connects to. And the phone can't tell which.
    Thanks for you reply.
    What do you mean by"unknown" carrier indication

    On my side, when the issue is present, in the *#*#4636#*#* menu I have:
    Current Network : Free (It's my carrier name => OK)
    Set prefered network type : UNKNOWN

    Just to be sure, can you confirm me that even if current network is still correct, if the set prefered network type jump to UNKOWN, the issue is directly link to the SIM card ?

    Thanks
    10-05-2018 01:07 AM

Similar Threads

  1. Splashes of color in lock screen notifications?
    By Nauga in forum Google Pixel 2 & Pixel 2 XL
    Replies: 5
    Last Post: 02-03-2019, 09:22 PM
  2. Replies: 1
    Last Post: 10-04-2018, 03:45 PM
  3. Change Timeout When On A Call
    By Mayor111 in forum Samsung Galaxy Note 9
    Replies: 2
    Last Post: 10-04-2018, 11:35 AM
  4. i cannot listen when any one call me without loudspeaker
    By Android Central Question in forum Ask a Question
    Replies: 1
    Last Post: 10-04-2018, 09:51 AM
  5. Replies: 2
    Last Post: 10-04-2018, 09:47 AM
LINK TO POST COPIED TO CLIPBOARD