After installing Custom ROM, I LOST DATA, 3G and 4G not working!!!
If you lost data, 3G, or 4G after installing custom ROM, it’s most likely due to APN settings.
Many carriers automatically set the APN settings for you when you install a custom ROM but sometimes this may not happen.
To fix, you simply need to Google your APN settings and input it in your Android smartphone.
For example, AT&T APN settings are:
MMS Proxy: wireless.cingular.com
MMS Port: 80
APN type: default,supl,mms
To change add APN settings, go to Settings->Wireless & Networks->Mobile Networks->Access Point Names.
APN stands for “Access Point Names”.