i found a solution for the flashing power light problems. Its a bit late for this thread, but it seems that alot of people have this problem so i post it here anyway.
My Acer 7750G had exactly the same charging problems, especially when playing games. It first occured after a year and became more frequent over time, until i coudn't even watch youtube videos.
Since my 2 year warranty is gone I opened my notebook myself and discovered that the power jack cable(see first pic) looked strange. The cable near the connector to the mainboard isn't enough insulated and leakage appears under full power (current flows between the cables). Then the mainboard doesn't get enough power anymore and changes into this flashing state without charging further. The leakage causes alot of heat which melts and destroyes the insulation further (visible: the red cable turned brown). So the problem intensifies over time.
thanks to my tutor who gave me this explanation
I just replaced the power jack cable with a new one(about £8). My notebook works fine again, already tested it by playing a few hours without any problem.
Important: there are alot of different types of power jack cables and each model, might have a different one so I can't suggest any. Even I bought a wrong cable which has a only slighly different connector. So if you do it yourself take a close look on your cable.
I study Electric Power Engineering and have some experience with Electronics. If you don't have any, I recommend to use a computer repair service!
If you do it yourself you probably loose your warranty by opening the notebook and risk to destroy other components if not careful.
Its on your on risk!!!
the power jack cable
If alot of people want to do it themself, I might write guide to how to open the notebook.
Hope this solution helps other aswell :)