i have this exact same problem with a v3 571 using windows 7home basic.  Could there not be a bad connection between the charger input port and the connector on the motherboard... infact where would one find a dissassembly manual so i can check proper... although i have already dismantled before finding this post... silly me, but i have not done too badly at all. i want to test the cable running from the power input port to the motherboard, i can only think that that could be the reason. question to ace.... why would doing the in and out thing help, would that be maybe the contacts arent making proper contact? i discovered while all plugged in and pushing power button repeatedly the blue light comes on every other press or so.  also im not getting the 10 second charge light like the windows 8 machine anymore... it has just totally stopped... if i charge the battery somehow i think that may help... im gna get my boets acer aspire battery so i can get power and run a few tests using hirens maybe. just the lights coming on now and then with every press tells me no power is been kept... my boet did charge this battery in his laptop and it did charge so it cant be the battery neither... he ran out of ideas and now its by me.  could anything possibly be wrong on the board? i hope for an speedy suggestion, if i make any discoveries then i will post ok.

I have the same problem and I have been trying to fix it (on and off) for 8 months.  I have 2 identical Gateway NV56R laptops (Acers).  1 of them stopped charging the battery and it even stopped running off the power cord (at the same time).  The computer will only run on a charged battery.  It will not run on the power cord (with or w/o a battery installed) and it will not charge a battery (whether the computer is turned on or off).  What I had to do was charge batteries with my good laptop but use them in the broken one.  Basically, when I plug in the laptop, the indicator light on the front left of the computer and the Windows Battery Management software both say that it is "Plugged in and charging".  Then after 15 seconds, the indicator light goes off and the software gives me the life of the battery, like it does not think that it is plugged in.  No warnings, messages, or balloons to tell me what happened.  Here is a video of the event (http://youtu.be/483H--CY_i8). 

Since I had an identical laptop, I easily eliminated the power cord/charger and the battery.  So I bought a new DC jack and installed it.  Nothing.  I marked it up as a bad motherboard and lived with it.  Months later, I performed a system recovery just incase it was a corrupt device driver.  Nothing.  I am not having any luck finding information on the charging circuitry for these computers.  I have taken it to several computer repair guys and have struck out with all of them.  They say that I need a new motherboard but they cannot tell me what is wrong with the one that I have to convince me that this will fix the problem.  Is there anyone knowledgeable enough to help me diagnose this issue so that I can get it fixed?

Since I can only run on battery power, it will not let me update the BIOS.  Since I am the same version as my good laptop, this shouldn't be my problem.  Any other suggestions?

Both computers are running Windows 7 64-bit.  It is what came on the computer originally.

OK, I have updated the BIOS to the latest and greatest, and the problem still exists.  The problem is that the computer only recognizes that I am plugged into the power outlet for 15 seconds and then it does not recognized the plugged in status.  While I was updating the BIOS, I checked that this condition was present in SAFE MODE and it is.