Saludos.
He intentado como bien me dices, pero por lo visto algo hago mal o no se puede. Una captura de pantalla de lo que me dice sony companiom, estando el movil apagado.
El *.log de flashtools lo he acortado pero he marcado en negrita los errores que me daba.
Código:
04/028/2019 18:28:08 - INFO - Flashtool Version 0.9.26.0 built on 20-07-2019 17:30:00
04/028/2019 18:28:08 - INFO - Searching for a web proxy
04/029/2019 18:29:05 - INFO - No proxy found, using direct connection
04/029/2019 18:29:06 - INFO - Loading devices database
04/029/2019 18:29:06 - INFO - Loaded 118 devices
04/029/2019 18:29:06 - INFO - Starting phone detection
04/029/2019 18:29:09 - INFO - Device disconnected
04/029/2019 18:29:22 - INFO - Flash canceled
04/029/2019 18:29:42 - INFO - Selected Bundle for Sony Xperia XZ Premium(G8141). FW release : 47.2.A.10.107. Customization : Customized CE1
04/029/2019 18:29:42 - INFO - Preparing files for flashing
04/029/2019 18:29:56 - INFO - Please connect your device into flashmode.
04/030/2019 18:30:06 - INFO - Using Gordon gate drivers version 3.1.0.0
04/030/2019 18:30:07 - INFO - USB buffer size set to 512K
04/030/2019 18:30:07 - INFO - Opening device for R/W
04/030/2019 18:30:08 - INFO - Device ready for R/W.
04/030/2019 18:30:08 - INFO - Reading device information
04/030/2019 18:30:08 - INFO - Reading phone properties
04/030/2019 18:30:08 - INFO - Sending getvar:max-download-size
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:version
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:version-bootloader
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:version-baseband
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:product
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:serialno
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:secure
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Sector-size
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Version-sony
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:USB-version
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:max-download-size
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Loader-version
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Phone-id
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Device-id
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Rooting-status
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Sector-size
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Ufs-info
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Emmc-info
04/030/2019 18:30:08 - INFO - getvar status : FAIL
04/030/2019 18:30:08 - WARN - Emmc-info not supported
04/030/2019 18:30:08 - INFO - Sending getvar:Default-security
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Platform-id
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Keystore-counter
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Security-state
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:S1-root
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Sake-root
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Battery
04/030/2019 18:30:08 - INFO - getvar status : FAIL
04/030/2019 18:30:08 - WARN - Battery not supported
04/030/2019 18:30:08 - INFO - Sending getvar:Frp-partition
04/030/2019 18:30:08 - INFO - getvar status : OKAY
04/030/2019 18:30:08 - INFO - Sending getvar:Stored-security-state
04/030/2019 18:30:08 - INFO - getvar status : FAIL
04/030/2019 18:30:08 - WARN - Stored-security-state not supported
04/030/2019 18:30:08 - INFO - Sending getvar:Keystore-xcs
04/030/2019 18:30:08 - INFO - getvar status : FAIL
04/030/2019 18:30:08 - WARN - Keystore-xcs not supported
04/033/2019 18:33:57 - WARN - TA Unit 2212 is excluded from bundle
04/033/2019 18:33:57 - INFO - Writing TA unit 00000964 to partition 2
04/033/2019 18:33:57 - INFO - download:00000001
04/033/2019 18:33:57 - INFO - download status : OKAY
04/033/2019 18:33:57 - INFO - Write-TA:2:2404
04/033/2019 18:33:57 - INFO - Write-TA status : OKAY
04/033/2019 18:33:57 - INFO - Writing TA unit 0000090C to partition 2
04/033/2019 18:33:57 - INFO - download:00000001
04/033/2019 18:33:57 - INFO - download status : OKAY
04/033/2019 18:33:57 - INFO - Write-TA:2:2316
04/033/2019 18:33:57 - INFO - Write-TA status : OKAY
04/033/2019 18:33:57 - INFO - Writing TA unit 0000091A to partition 2
04/033/2019 18:33:57 - INFO - download:00000001
04/033/2019 18:33:57 - INFO - download status : OKAY
04/033/2019 18:33:57 - INFO - Write-TA:2:2330
04/033/2019 18:33:57 - INFO - Write-TA status : OKAY
04/033/2019 18:33:57 - WARN - TA Unit 2550 is excluded from bundle
04/033/2019 18:33:57 - INFO - Writing TA unit 000009A9 to partition 2
04/033/2019 18:33:57 - INFO - download:00000001
04/033/2019 18:33:57 - INFO - download status : OKAY
04/033/2019 18:33:57 - INFO - Write-TA:2:2473
04/033/2019 18:33:57 - INFO - Write-TA status : OKAY
04/033/2019 18:33:57 - WARN - TA Unit 2553 is excluded from bundle
18:33:58 - INFO - Sending Sync
04/033/2019 18:33:59 - INFO - Sync status : OKAY
04/033/2019 18:33:59 - INFO - Sending powerdown
04/033/2019 18:33:59 - INFO - powerdown status : OKAY
04/034/2019 18:34:05 - INFO - Device disconnected
</div>
Gracias y un saludo.