Problem with power supply!!

Hello, So I bought my acer 7750G some months ago and everything was fine until the beginning of march.

Everytime I start a game, after a little while the playing, the charger stops working and the power button starts blinking until I plug it out. If I plug in again it does the same

It ALWAYS happen, and if I quit game and plug in the charger it works normally.

Now the stupid part is, I sent in my computer to acer support tech center for them to fix it and I got the piece of trash back with a note saying "no problem found"!! I even stuck a note on my computer describing the problem and pulled forward some simple games on deskop for them to try.
So I got it back from them booted up a game and same problem occured AGAIN..

Can you guys please help? Acer wont help me.

http://www.techspot.com/community/topics/problem-with-power-supply.178924/ <------- these people have the same issue

Try replacing the laptops battery...

Yes the battery may be one issue, but also what may be happening is that when you run the game, it overheats one of the internal components which in turn overheats the battery. When the battery overheats the computer usually shuts down to prevent further damage to itself.

If you are still having issues feel free to contact me.

I have tried to fix it alot now and came to some resultat:

When I disable ATI Powerplay settings, I can play games as usual BUT it laggs like hell so not really playable.
It seems also like if I went with powerplay setting for a while without charger and then try connect the charger with powerplay disabled it wont work, it will stop charging ect.

Any ideas? Acer wont help me at all, just sent me a note back twice now "no issue found"...

Again... try replacing the battery

"When the battery overheats the computer usually shuts down to prevent further damage to itself"...

If the battery overheats enough to cause the laptop to shut down, it is way past the time to replace it!

Not a chance its wrong with the battery. If I run WITHOUT the battery, the computer randomly dies, instead of killing of the charger lïke it does when I have battery connected.

Again I think its related to my Graphics card, since with ATI Powerplay disabled I don't encounter this problem (though gaming is laggy like HELL).

Any other ideas? I'm suffering here

edit: Graphic card: ATI radeon HD 6850M

If the GPU is separate from the motherboard have it replaced. If it is integrated into the motherboard, you know what you have to do then. The GPU may be overheating, and you may be able to reapply any thermal pads or paste

I hadnt thought of the GPU, good catch Tmagic