Hi @shayne, sorry to hear the issue on your Flash2 and thank you for providing us information on the issue. I would like you to try this steps to try to fix the issue on SIM Card.
1.Please insert another SIM card to your phone or re-insert your SIM card again to confirm whether this is your SIM card problem or not and please make sure you are using a Micro SIM
2. If your SIM card isn't working, please contact your service provider for help.
3. If SIM card is working on another phone, please upgrade your phone's Fota SW to the latest version.
If you want to factory reset the Flash 2 please follow this steps
Warning: this action will erase all your personal information, files and downloaded apps.
In power on state:
Make sure that your phone is charged at least 80% before doing a factory reset
1)Click " Settings" -> " Backup & reset" -> " Factory data reset" -> " reset phone"
In Power off state:
1) Long press Power Key and Volume Up Key
2) Use volume up key to select "Recovery Mode" and use volume down key to confirm.
3) Press Power Key and Volume Up Key together twice to enter recovery mode.
4) Press volume down key to select Wipe data/ factory reset
3) Press volume down key to select " Yes---delete all user data".
Warning: this action will erase all your personal information and downloaded apps.
. If problem still exists, please contact our service center for checking
With regards to overheating issues try to search for software update by clicking on Settings -> under System (About Phone) -> click on Wireless update and check for updates. If your flash is currently updated, I advise you to go to our service center for checking. Godspeed!