Remove the USB drive after reboot (otherwise it may reflash). Perform a factory reset from the OSD menu.
If you have already sourced the correct firmware file (usually named allinstall.pkg or MstarUpgrade.bin ), follow these steps provided by technical guides : Cvte Msd338 512m Update
Users typically seek this update for one of four reasons: Remove the USB drive after reboot (otherwise it may reflash)
If the TV is stuck on the logo after an update, it is often due to using the wrong resolution firmware. A "soft reset" can sometimes be achieved by disconnecting the power for 10 minutes. Cvte Msd338 512m Update
: Go to Device Preferences or System > About .