No service after battery change

Hi,

The battery of my iphone 5 died once, I changed it without issue.

It has died once again and I ordered a new battery... I checked the SKU nr and it is exactly the same model as the one which was working.

After change it shows "No service" and doesnt ask to unlock the SIM.

I decided to put back the old battery which was nearly dead... got the service back...

One friend had an original battery to borrow me. I made the test and no service again with this original battery.

I tried again the new battery, no service.

I only have network connectivity when I plug the nearly dead battery.

I've connected to Wifi to be sure to get the correct date and time.

I've doubled checked every transistors on the main board, nothing is damaged.

The 3g antenna is clean and correctly plugged....

I don't really know what to do now, any advice ?