Resolving Errors: Invalid or Missing SIM card, Invalid IMEI, and Cellular Network "Unknown"

[Nikita H]

Resolving Errors: Invalid or Missing SIM card, Invalid IMEI, and Cellular Network "Unknown"

*EDITS NOTED WITH SINGLE ASTERISKS

Phone: BLU Life XL (Model: L050U - dual SIM - unlocked from manufacturer)
OS: Android 5.1 (LOLLIPOP_MR1)
Provider: H2O Wireless (runs on AT&T's GSM 4G LTE network)

I have had the same cell phone, OS, service provider, and SIM card since Oct. 2017 without any prior issues.

I can't send/receive calls or texts, and I can only access the Internet via WiFi.

*According to the CTIA Wireless Association (US) website, my phone's IMEI is not reported as lost/stolen. When I typed in the IMEI1 number, the website gave me the correct manufacturer and model of my phone.

Below, I have listed 4 errors I need to resolve so that I may reconnect to my cellular network.

**I am an amateur, so please excuse me if I have given unnecessary, incorrect, or redundant information. I am here to learn

INVALID OR MISSING SIM CARD:

I contacted my provider regarding the "Invalid or Missing SIM card" error. After I completed a series of IT-directed diagnostic actions, the provider said there is likely some issue with the phone or the OS.

In Settings -> Wireless and Networks -> SIM cards, both of my SIM card slots are "grayed out". I can't turn either slot back on.

I would like to test the SIM card in another device, but I don't have another compatible device.

INVALID IMEI NUMBERS:

In Settings -> About device -> Status -> IMEI Information, the IMEI numbers are missing.

If I enter the dialer and type *#06#, I receive an Invalid IMEI error message.

I located the IMEI numbers under the battery of my phone, but I don't know the best way to restore the IMEI numbers on my OS.

*INCORRECT SERIAL NUMBER:

In Settings -> About device -> Status -> Serial Number, the phone's serial number is listed as 0123456789ABCDEF, which doesn't match the phone's real SN.

CELLULAR NETWORK "UNKNOWN":

In Settings -> Wireless & networks -> More ->, the Cellular Networks option is "grayed out".

If I enter the dialer and type *#*#*4636#*#*, I enter the testing menu.

In this menu, "Set preferred network type" is set to "Unknown".

When I try to choose a different network, the drop-down menu option I choose responds to touch, but doesn't actually change the preferred network from "Unknown".

LASTLY:

If there are any common apps or settings I may have used or updated that could cause these errors to occur, please let me know.

After proper backup of my files, would a factory reset solve these errors or complicate them?

Thank you in advance for your assistance

 

[B. Diddy]

Re: Resolving Errors: Invalid or Missing SIM card, Invalid IMEI, and Cellular Network "Unknown"

Welcome to Android Central! I agree that a factory reset is probably the best next step. Definitely make sure you backup your important data first. Let us know if the problem persists!

 

[Nikita H]

Re: Resolving Errors: Invalid or Missing SIM card, Invalid IMEI, and Cellular Network "Unknown"

I factory reset my phone, and my IMEI numbers have been restored.

I can send/receive calls and text messages, as well as accessing the internet.

However, the factory reset did not restore my serial number. Why is this? Will this cause me issues later?

Thank you for your help,

NH

 

[B. Diddy]

Re: Resolving Errors: Invalid or Missing SIM card, Invalid IMEI, and Cellular Network "Unknown"

I doubt the S/N will matter, as long as your IMEI is intact. Do you still have the original packaging for the phone? Also, does that phone have a user-removable battery? If so, the S/N might also be on a sticker inside the phone.

 

[Rukbat]

Re: Resolving Errors: Invalid or Missing SIM card, Invalid IMEI, and Cellular Network "Unknown"

Almost no one ever looks at a cellphone's serial number - cellphones go by IMEI numbers. If it works now, I wouldn't worry about the serial number.