Try another known good charger, also take the battery out to see if that makes any difference.
The socket for your laptop sounds to be worn out, this happens often, there are many cheap charger port replacement services out there.
Theres a thread about it no working on laptops with Realtek possibly this might be it
http://musescore.org/en/node/16849
Try updating your sound drivers
Theres a thread about it no working on laptops with Realtek possibly this might be it
http://musescore.org/en/node/16849
Try updating your sound drivers
Are your audio levels turned down in the system tray > over on the right hand side of the screen.
There should be a audio level bar for Internet Explorer (being youtube)
and another for MuseScore.
One of these sounds to be like it's lowered, is it ever since you installed this software that...
Really depends on what you want, tell us as to what you want the laptop to do.
Are you wanting good graphics
Lenovo
Graphic Processor 512 MB AMD Radeon HD 8650G (Integrated) and 2 GB ATI Sunpro HD 8570 Graphics (Dedicated)
HP
Graphic Processor 512 MB AMD Radeon HD 7660G (Integrated) and 2 GB...
I tried the Acer website, but nothing came up when I entered the serial number and model number.
However I did find a video on youtube that might help.
http://www.youtube.com/watch?v=XehZr6dnMho - This says LED backlit.
C..