Laptop Battery Charger Buzzing?

Long story short, the cord on my Asus laptop battery charger was split in half the other day. To fix it I spliced the two pieced together with a wire nut and wrapped it in lots of electrical tape. Now, whenever I plug it in to the wall, whether the other end is plugged in to the laptop or not, I get a buzzing sound. I have already purchased a new charger, better to be safe than sorry, but I would like to know if this charger is shot, or can I keep it as a back up?

From an electrical stand point its a good candidate for the trash.
Ya got your new one. your good.

After reading about somebody being electrocuted from a faulty charger, I would just throw it out, better to be safe than sorry.
http://m.smh.com.au/nsw/faulty-usb-...or-sheryl-aldeguers-death-20140627-zsoc8.html

Thanks for the advice. I will toss it.

Of course now the new battery that I bought too isn't charging! I guess you get what you pay for. It bought it cheap off of Amazon in hopes that it would last at least a year. Normally the batteries I buy are about $80 - $90. This was $18. Is there any other reason, besides it being a dud, that it wouldn't charge? I know the new charger is good, it charges my old battery without any problems.

Some non OEM batteries won't work correctly in some laptops. Some won't be detected by the machine and others just simply won't charge up all the way. Definitely return it.

The buzzing you hear is transformer hysteresis. The core has probably delaminated. Time for a new one.