The LG support website does not provide an online manual for the LG420G cellphone, as of May 2015. However, the support website provides a data sheet and quick-start guide for the cellphone, as well as support options via email or live chat.
The LG420G cellphone data sheet provides specifications of the cellphone. The quick-start guide provides basic instructions on using the cellphone such as using the menus, setting sounds and entering text.
Alternatively, contact LG support by email, and enter contact information and details of the inquiry. Live chat with LG support is available on weekdays from 8 a.m. to 8 p.m. CST.