Keypad is not showing on lock screen and turned into Emergency Mode

[Android Central Question]

Hi,
I have a serious trouble with my phone.
My phone's model is sm-g5108q(SAMSUNG G5108Q Galaxy Core Max).
It is manufactured in 2014 and of course it's old phone.
Oneday when i power on my phone, i can't input password because keyboard is not appearing.
It seems samsung keyboard error.
Password type is normal password(not pin,pattern,face,fingerprint)
I reset my phone lots of times, but always the same results.
I can't perform the Factory reset becauseof loss of data.

I googled my issue all day long, so i found solution. That's the way to use usb-key board(with otc cable)
After i connected usb-key to the phone (with otc cable), but nothing happend, I disappointed.
I tried it on other phone, usb-key works well on lock screen on that phone.
I looked thorugh my phone,omg, my phone turned into Emergency mode(i don't know the reason).
In Emergency mode, it didn't permit to connect other device to save battery.
I googled again to find the method to disable Emergency Mode.
On Recently produced phone, after pressing power button, there was a menu "Enable/Disable Emergency Mode".
But my phone is old one, so in order to disable Emergency mode, i think i should login my phone.

So i can't do anything.
To use usbkeyboard, i should disable Emergency mode.
To disable Emergency mode, i should login phone.
of course, i know my password.
Please help me, i will appreciate any solutions or advices.

 

[methodman89]

You have a 50 dollar phone with a hundred dollar problem afaict. Maybe try a trade in s7 for a while.

 

[Rukbat]

I looked thorugh my phone,omg, my phone turned into Emergency mode(i don't know the reason).

The reason is that the phone isn't connecting to the carrier's network. Bad SIM card? Bad phone? Your account information (in their database) got corrupted? Bring it to the carrier to find out. (Most major carriers will just replace a bad SIM card, but some of the smaller ones will charge you for one if the old one goes bad.)