Hello I know how to solve your Problem but so hard to wait but now I can surely repair your
Samsung Galaxy J200GU because I already download the
Firmware. Just Contact me on facebook (
https://www.facebook.com/Johannah.Kenneth ) and Message me. If you want to download too long like 8 Hours den it will error if your connection will TIMEOUT thats why I already have mine if you interested just contact if only for
Samsung Galaxy J200GU if you want to know how to repair any Model with same problem just Contact me also I will teach you step by step.