LG -E425 Service Manual page 165

11. HIDDEN MENU
GPS BT Wifi Test
GPS(RF) test : CNO is some value : OK
Bluetooth Scanning is PASS : OK
WiFi Scanning is PASS : OK
FM Radio Test
87.5 Mhz is scanned automatically
-> Connect ear-jack
Sound Loopback Test
"On" is test mode on
"Off" is test mode off
LGE Internal Use Only - 165 - Copyright © 2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes