Problem with my power cord

I keep my computer plugged in when I'm at home, but my power cord keeps "shutting itself off" and stops charging. So sometimes I check my battery power and there's like 24% left. My battery seems to be holding a charge for now, but my power cord seems to randomly fail. Never in my life have I ever heard of power cords failing-I'm sure it happens but this is ridiculous.

 

if your still under warranty, bring it to an apple store.

 

You mean your Mac charger is damaged? Arrange an appointment with AppleCare and take it to an Apple store if your Mac is under warranty. If it is a problem with the charger itself, Apple may replace it. If you bent the cord too much or something, then you might have to buy a new charger.

 

If it's a cord an not an adapter, then yes, I'd agree, If it's an AC Adapter, they will shut down due to thermal overload (overheating). It's a built in safety feature to keep your adapter from melting and doing things like starting a fire.

First, if you're able to yourself, check the output voltage from the outlet it's plugged into. If it's plugged into a standard power strip, get rid of it - those things are fire hazards waiting to burn down your house. I found that out the hard way about 10 years ago when one caused a fire in my daughter's room. Fortunately I was able to put it out - luckily it had began under a window, which caused a temporary firebreak. But it was nearing the ceiling when I finally killed it. I was also lucky my wife was home that day - I was out cold, recovering from a major spine operation and didn't hear the smoke alarm go off. My old submarine training woke me up fast though when I heard her say "Fire". Some things always stay with you.

Everything in my house now is either on a UPS or AVR/UPS, but not a plain power strip.

The voltage should be within 2- 5 volts of your regional voltage. If you were connected through a power strip, and the output voltage is good at the outlet, plug directly into the outlet and see if you get a different result. Also, try a different outlet - if the same thing happens you'll know it's either system or adapter/cord related.

Inspect the Cord/Adapter

If the cord is the 2 part type where one plugs into the adapter and the adapter then plugs into the system, get a good flashlight and look at the terminals where the cord plugs into the adapter, as well as the prongs on the plug itself. See if there is any black carbon buildup or melted metal. This indicates a bad connection and shorting is occurring.

Get a magnifier and do a careful examination of the cord itself as well and make sure it hasn't been cut, nicked or otherwise compromised in any way by the insulation being removed. Cords should be unfolded when possible as well - the more they're bound or wrapped when energized, the more resistance there is and the more heat they generate. More resistance equals less voltage getting to the endpoint. Not much, but if it's compounding another problem it can't help.

If it's just the system shutting down, then it's likely your Power settings were changed somehow. Either way, check your Admin Event logs to see if something specific is causing it.

 

I don't know, when the charger "shuts off" and the computer goes into battery mode, I have to fiddle with the charger to get it back to plugged in mode. I'll try plugging it straight into the wall and see if that changes anything.

 

Looks like I was plugging it into a dead power strip or a bad outlet, but is it normal for the amperage to be as low as ~670 when it's charging? Well anyways at least the amperage is positive.

Thanks for your help!