I have Samsung Galaxy Tab GT-P7100 (Tab 10.1v). It was faulty and I bought it on eBay specially for repair. I am engaged repair of tablets and SAMSUNG phones. It had the broken display and came without battery. I restored it. Now this Tab works! However I see that it has IMEI generic 0049... and Android 3.0.1. I also updated it to 4.0.4, but then again returned to 3.0.1. This TAB now perfectly works! But one problem remained. I want to restore its native IMEI, but I am not able to do it as PC doesn't define its modem of this tablet! I flashed different modems and process always comes to an end successfully. I see the new modem in properties of a tablet. However PC in any way doesn't define the tablet modem. Only in the Download mode PC will define the modem. But in this mode I can't change IMEI. I think that this is a problem modem configuration files. In efs folder there are only few files. It isn't enough of them. I think that it is a problem which doesn't allow to define the modem in PC. Possible it is my problem. It is possible to eat here my problem. Somebody can help me and give me full backup of efs folder for a working P7100 tablet? It will allow me to have a full and correct set of files in efs. Then I will change IMEI on native for my tablet.