Possible causes of 4G drop

Question：4G invalid

Check whether 4G drops occasionally or all the time?

Pull out the SIM card in the MDVR and insert it into the mobile phone to confirm whether there is still communication traffic

Check whether the 4G antenna is firmly plugged into the MDVR；

Insert the 4G antenna that works normally on other MDVR into this MDVR；

Put the MDVR 4G antenna in an outdoor open place and check the signal strength；

Open the mdvr shell and replace it with a good 4G feeder line. The feeder line may have poor contact；

4G module damaged.Open the mdvr shell and replace the 4G modules working normally on other mdvr into this mdvr.