If the power is interrupted, the motherboard can become "bricked," requiring professional repair. Always ensure your firmware version matches your platform (e.g., don't install an R51M file on an RT51 TV).
TCL does not always host every version on a public-facing website, so enthusiasts and official support channels are the best sources: 1. Official TCL Support Pages (Regional) link download tcl firmware for all models
Before you download, it’s important to know which "flavor" of firmware your TV uses. TCL generally uses two main update formats: If the power is interrupted, the motherboard can