If the screen is working, you may see a message like "Upgrading software, please do not turn off".
If you need to access the service menu after installation to adjust settings like panel mapping or logo, the code is typically Menu + 1147 . Download MS338 PB802 EMMC TOSHIBA FLASH rar
Do not interrupt the power. The update is finished when the indicator light stops blinking or blinks at a much faster rate. If the screen is working, you may see