Hongdian H7921/H7920 Basic 3G/4G Router - Manual (Page 122)

7 FAQ H792x 3G/4G Router
7 -88 (2014-05-28)
7.3 Hardware Failure
7.3.2 All LED dark
Phenomenon
Router LED all dark
Possible Reason
 Power supply does not match, it should be 5-36VDC
 No power supply
Solution
 Make sure the power supply is 5～36VDC
 Check the power adapter and cable connection
7.3.3 SIM Slot
Phenomenon
Cannot insert SIM card
Possible Reason
 SIM slot damaged
 SIM card wrong direction
Solution
 SIM slot damaged, please contact us to repair
 Check the SIM card direction, please make sure the SIM goldfinger is up
7.3.4 Ethernet Connection
Phenomenon
LAN LED dark, cannot visit router WEB GUI
Possible Reason
 Ethernet cable connection problem
 Ethernet cable damage
 PC end network card abnormal
Solution
 Re-connect Ethernet cable
 Change a Ethernet cable
 Check network card setting on PC end