What reasons for outdoor chrismtas led string lights not to work, even if electric signal detected?

What reasons for outdoor chrismtas led string lights not to work, even if electric signal detected?

What reasons for outdoor chrismtas led string lights not to work, even if electric signal detected?

I have 80m outdoor LED lights which worked last year. This year they wont come on. Thing is, if I use a electricity detector pen, it shows electric IS flowing through the whole thing. I can't imagine ALL the LEDs have gone? And they are ones that are supposed to keep the circuit working even if one fails.

So I just wondered if anyone knows what reason could the bulbs not be working even though electric is flowing through it?

Thanks

by lozcozard

This has been automatically posted in the DIYNot Forum on DIY Talk. The new DIY Forum