To do a firmware update, you have to have a functioning television.
If it's actually showing a screen that's in bootloop, the 30800-000499 mainboard will require removal and flashed with special tooling. These boards are only $25 USD / $40 CAD, making it easier and cheaper just to purchase a replacement.
If the screen is black, verify the LCD is functioning by using a flashlight. If you find dim images, the B0101-000776 LED backlight strip may have failed, and/or the 30805-000371 power supply board. Start by inspecting this board closely, as there are two large 68µ capacitors that are prone to fail.
What model is Roku. X00100DKH666
What model is serial number X00100DKH666. And what power adapter does it need?
Serial Number vs ID with Roku can be confusing. Usually serial numbers starting with X00 are the devices digital S/N, not the one physically found on the unit marked S/N. The one on the Roku itself appears digitally as "Device ID".
X00 is often TV serial number.
Thank you so much . So I have to look on the back of the TV?
Well, the Roku TVs don't work like the Roku devices. If you're looking for a power supply, it will just be the brand and model number which should be on the back.