Hello, 

I've been using my Archer MR200 v4.1 for a while and it's worked a charm until today. 

Unfortunately, I started experiencing issues as the sim card was not detected. I confirm that I've tried restarting the modem multiple times, I rebooted it, reseted it to the factory settings, unplugged it with the sim card on with no success every time. 

Regarding the sim card. I tested two sim cards and the issue was still there. Just to be sure, I also tried both sim cards into another device and they're both working. The carriers of the sim card are Tim (Italy) and 3 (Ireland)

So long story short there seems to be an issue with the modem device itself. Do you have any other recommendations? 
 

The device was only bought in June last year