If "r1.5.6.1" referred to a specific document revision number, please note that IMEI guidelines are typically versioned as "Version 15" , "Version 16" , etc. There is no standard document officially labeled "Revision 1.5.6.1".
Input the 15-digit IMEI found on the device's original sticker or packaging. write imei r1.5.6.1
Flashing a full firmware (especially a wrong one) can wipe the NVRAM partition where the IMEI is stored. Result: IMEI shows as null , 000000000000000 , or unknown . Writing the original back is the only fix. If "r1
| ✅ Legitimate | ❌ Illegal | |----------------|-------------| | Restoring your own original IMEI | Cloning another phone’s IMEI | | Repairing null IMEI after software crash | Changing IMEI to bypass blacklist | | Carrier-approved motherboard IMEI transfer | Selling phones with altered IMEI | Flashing a full firmware (especially a wrong one)