flipping adapter on external HDD got it "alive"

[paparazzo79]

Hi guys.
The adapter for my external WD My Book was left on the wall socket (extender).
I connected the USB cable to the laptop and nothing the disk was dead (I couldn't hear motors).
Gosh I got scared that my HDD died on me...I tried other PCs same issue.
Then I unpluged the adapter from wall socket(extender) and just flipped it other direction.Now it works.
Now I want to know,curiosity killed me,why does it matter in this case,how to adapter is plugged in.

[stj]

because the contacts in it are bent or shit?
you need to check that - if it happens with a high current device it could arc and catch fire.

[diif]

If you were worried you'd lost it, that's an indication you don't have a back up.

[paparazzo79]

I think you guys did not understand my question.
Perhaps I need to draw?

[eccerr0r]

Simple explanation that doesn't make any assumptions:

You're getting DC electricity at your wall socket and your power supply is half wave.

However this is very unlikely and probably as stj says - your contacts in the extension cord are bad and plugging it in the other way happened to make things connect properly. AC electricity shouldn't matter which way you plug it in as the next cycle it looks like the same as before.

If your electricity is not quite clean like has a large DC offset it could do this, while still "AC" it will confuse cheap power supplies that omit a bridge rectifier (or if the bridge rectifier is bad).

[paparazzo79]

Originally Posted by eccerr0r

Simple explanation that doesn't make any assumptions:

You're getting DC electricity at your wall socket and your power supply is half wave.

However this is very unlikely and probably as stj says - your contacts in the extension cord are bad and plugging it in the other way happened to make things connect properly. AC electricity shouldn't matter which way you plug it in as the next cycle it looks like the same as before.

If your electricity is not quite clean like has a large DC offset it could do this, while still "AC" it will confuse cheap power supplies that omit a bridge rectifier (or if the bridge rectifier is bad).

Connected to brand new surge protector.
Doesn't matter,seems like I need to do a video so I can explain things here.

[paparazzo79]

Ok so I draw the explanation on the pics:
Works not working meant on External HDD My Book 8TB

[petehall347]

wire might be broken here ...

[paparazzo79]

Nope.

[sam_sam_sam]

Please post a short video of what is going on here