The Ac Adapter LED going On & Off when connected to the system indicates that motherboard is faulty. To confirm that you may try with a known good Ac adapter and if the issue persists, consider replacing it.
The smell from the system itself indicates that there is some short on the motherboard. I recommend you to get the system serviced. Please click on the link below to check the warranty of the system. In case the system is under warranty, send me a private message with the system service tag to assist you further. Please click on my name and click Start Conversation to send me a private message.
In case the system is out of warranty, let me know the region you to belong to, to provide the contact information to get the system serviced which is paid support.