bueno man yo tambien tenia ese problema y
lo q ise fue conectarlo al xs++
no entiendo mucho de esto pero aparecio una opcion para actualizar el flash algo asi
y le si aceptar y estubo cargando un rato y luego ya pude flashearlo
"creo q el problema esta q tu cel es cid 49 erom cid 49"

esto me arrojo el xs++ y se soluciono

20:54:14| XS++ v3.2 Dev1 (Crystal) Ready !
20:54:14| Executed on Microsoft Windows XP
20:54:19|
20:54:19| Attempting to open the interface...
20:54:19|
20:54:19| TURN OFF PHONE!
20:54:19| Hold 'C' button on phone and connect phone NOW.
20:54:19| You have 30 seconds...
20:54:19|
20:54:23| Baseband ID: 9900
20:54:23| Protocol Version: 3.1
20:54:23| Phone name detected!
20:54:23|
20:54:23| Profiling SEMC phone...
20:54:23| Platform: DB2020
20:54:23| OTP CID: 49
20:54:23| EROM CID: 49
20:54:23| EROM Color: Red
20:54:23| IMEI: 35220601xxxxxx
20:54:23| Phone ID: K790
20:54:23| Region: AMERICA_2
20:54:23| CDA: CDA102535/22 R5A
20:54:23| Firmware Version: R1CG001
20:54:23| EROM: R3A016
20:54:23| Ready for operation!
20:54:31|
20:54:31| Sending db2020_cid01_prodid_p3j.bin...
20:54:31| Applet ID: 070129 0950 NGUCXC1250330_DB2020_PRODUCTIONIDLOADER_P3J
20:54:31| This is a PRODUCTION_ID loader
20:54:31|
20:54:31| Sending db2020_mem_patcher_cid49_r2a006.bin...
20:54:32| Applet ID: 061205 1523 HANCXC9876543210_DB2020_MEM_PATCHER_R2A006 0
20:54:32| This is a MEM_PATCHER loader
20:54:32|
20:54:32| Sending db2020_red49_cs_r3a009.bin...
20:54:33| Applet ID: 070410 1557 HANCXC1250562_DB2020_CSLOADER_R3A009
20:54:33| This is a CHIPSELECT loader
20:54:33| Activating loader...
20:54:33| Activating GDFS...
20:54:45| This loader is UNLOCKED
20:54:45| Run GDFS-script...
20:54:45| Wrote 1 variables!
20:54:45| Read 0 variables to .\Backup\K790_35220601xxxxxx_GDFSSCRIPT_OUTPUT_110 023205445.script!
20:54:45| GDFS-Script was run successfully!
20:54:45| GDFS operation was successful
20:54:47| Disconnected... Unplug the phone
20:54:59|
20:54:59| Attempting to open the interface...
20:54:59|
20:54:59| TURN OFF PHONE!
20:54:59| Hold 'C' button on phone and connect phone NOW.
20:54:59| You have 30 seconds...
20:54:59|
20:55:03| Baseband ID: 9900
20:55:03| Protocol Version: 3.1
20:55:03| Phone name detected!
20:55:03|
20:55:03| Profiling SEMC phone...
20:55:03| Platform: DB2020
20:55:03| OTP CID: 49
20:55:03| EROM CID: 52
20:55:03| EROM Color: Red
20:55:03| IMEI: 35220601xxxxxx
20:55:03| Phone ID: K790
20:55:03| Region: AMERICA_2
20:55:03| CDA: CDA102535/22 R5A
20:55:03| Firmware Version: R1CG001
20:55:03| EROM: R3A016
20:55:03| Ready for operation!
20:55:15|
20:55:15| Sending db2020_cid01_prodid_p3j.bin...
20:55:15| Applet ID: 070129 0950 NGUCXC1250330_DB2020_PRODUCTIONIDLOADER_P3J
20:55:15| This is a PRODUCTION_ID loader
20:55:15|
20:55:15| Sending db2020_mem_patcher_cid52_r2a006.bin...
20:55:16| Applet ID: 061205 1523 HANCXC9876543210_DB2020_MEM_PATCHER_R2A006 0
20:55:16| This is a MEM_PATCHER loader
20:55:16|
20:55:16| Sending db2020_cid52red_flash_r2a005.bin...
20:55:17| Shutting down...