Help LG optimus Not reading the SIM


I got my LG optimus one month before. I changed the SIM card for once, a week ago. Later when I tried to activate it with the previous SIM, it is not accepting it. Permanently showing the "No SIM card" message on the screen. Please help me with this as soon as possible.


I have the same issue...
I was just told I have a Optimus Hub Phone. I bought it at a Baja Pawn Shop! There is a red star or spot over the bars that show the signal strength. There are NO bars. It has a Moviestar sim card in it from Mexico. How or what do i do to make it work. I am a noob to this android type phone but know the iPhone I had before this one. Thanks for any help.

Model Number LG E510g
Android Version 2.3.4
Kernel Version
Build Number GRj22
Software Version LG-E510g-V10b