ASUS G71GX-RX05 Power Issue

Alrighty. Let me start off by saying - While I know quite a few things about computers, I am not an expert, so some concepts you might have to break down into laymen terms for me.

Anyway.
I have the ASUS G71GX-RX05 (Republic of Gamers one).

My power problem begins with the power cord.
The original power cord that I recieved would switch from AC Mode to Battery mode every once in a while, and if you jiggled the cord, it would switch as well.
What was happening with that one was that the metal extension of the cord somehow became too long, so the metal prong inside the power outlet of the computer wasn't getting to the important stuff it needed inside the cord.

So I replaced it.

The new cord worked fine....for about a month.
The problems started 2 days ago. I was minding my own business, surfing the web, when "AC Mode" blinked on the screen a couple times. It was doing it a couple times a day for those 2 days. Now tonight, it went ape, and it continuously blinks "AC mode" until I unplug it.
(I plugged in the old power cord, and it doesn't constantly blink.)

I looked the problem up, and saw that someone had a similar problem. They were told it could be because the power cord was not powerful enough, and so the battery was having difficulty charging.
So I figured if I disconnected the battery, the blinking would stop, and I was just going to use the cord as the power. But when I disconnected it, plugged the cord in and tried to turn on the computer, it wouldn't turn on. The lights blinked, but the computer would NOT switch on.
I was like...??!??!
So I plugged in the old cord and the computer came on just fine.

I looked at the power information on the new cord's brick and the old cord's brick.
Turns out the new one's output is 19v while the old one is 19.5v.
Would that small a voltage difference really cause all this trouble, or is there some underlying problem I'm not seeing here?

I have since put the battery back in, and I'm using the old faulty cord for now.

 

You could also have a marginal AC port on the pc.

 

It is not a good idea. You should get a replacement adapter that has the same voltage, this will eventually cause strange problems if you really push your machine. I'm not sure it's a problem if you just charge the battery with the system off, in any other scenario it is going to end badly.

 

Marginal port?

I honestly can't even use the computer when the new cord is in now because of that "AC mode" constantly popping up (it appears right in the middle of the screen with a big icon), so I'm using the old cord. As long as I dont shift the computer too much, i don't have a problem with it.

I figured I would just replace the cord, but I wanted to see if there was maybe some other thing I was missing before I went out and bought something I may not necessarily need.