How to make a LED / TV backlight tester miniseries part 3

How to make a LED / TV backlight tester miniseries part 3
in this video the construction and testing the tester

circuit diagrams
led tester
https://drive.google.com/file/d/1TPqSlVfKSqb4Iu2Lww7hOiruwv2lto7H/view?usp=sharing

led mains indicator
https://drive.google.com/file/d/1s6Yb63tgaxJy93R2jNtKxyGOj_WlWmGG/view?usp=sharing

volt meter
https://drive.google.com/file/d/1k-wbQW4GOIgklofQUtN9Qf8okr0VkSx1/view?usp=sharing

part 1
https://www.youtube.com/watch?v=IGgFjaaFd58&t=1s
part 2
https://www.youtube.com/watch?v=QJjnEtdYOSw&t=384s
part 3
https://www.youtube.com/watch?v=oS0ZcxQmKLM&t=6s
part 4
https://www.youtube.com/watch?v=auJKpo_h9is&t=15s