sim card problem on moto 4g

I have a moto 4g and recently have had some problems with it shutting down for no good reason and some problem getting it going again soft reboot holding power button for 2mins etc but have managed to get it going again any yesterday it happened last night and after repeated attempts to get some life in it i gave up. As i still have my old phone a Huawei assend g300 i removed sim card from the moto and using adapter for micro sim i put it in the old phone and all good.
This morning i thought i would have another go at the moto and lo and behold i kick started it into life i was well pleased with my good work but not for long, i took the sim card from one to the other and the moto now has no network with its sim card (virgin) i have pressed and clicked everything with no joy.
The sim is back in the old phone working fine the sim is not damaged so i dont know what to try next apart from buying a new phone.

sim card problem on moto 4g