Once the blinking stops or the TV reboots, remove the USB drive. The first boot after an update may take longer than usual. Common Troubleshooting T.MS638.733-ULTRA-HD-SMART TV-FIRMWARE - Facebook
A source for 4K-specific resolution firmware files. Installation Guide (Step-by-Step) t.ms638.733 firmware
Offers free downloads for various brands using this board. Once the blinking stops or the TV reboots,
Finding and installing the correct firmware is essential for resolving issues like "hanging on logo," boot loops, or software bugs. " boot loops
Download the correct firmware and copy the file (usually named allupgrade_ms638_733.bin or similar) to the root directory of the USB drive. Do not put it in a folder.