Netgear Telstra 4G Aircard 320u Lights Flashing

My Telstra Aircard 320u USB modem has been working fine until two days ago.  Since then when I plug it in, the power light flashes blue and amber.  Sometimes it connects to telstra (all lights blue) but only for a minute or two and then the power light starts flashing blue and amber and it disconnects.  What is wrong with it and how do I fix it?  I've tried on TP_Link router (which it has always worked on until two days ago) and my laptop.  Same result on both so it is definately the modem dongle.