describe the smell, if its acidic and harsh its probably electrical, if it smells like burning oil...it probably is, if it smells really sweet and humid its antifreeze/coolant, if it smells kinda like burning rubber it could be belts slipping, or a hose that has fallen and is melting etc, if you ask extremely specific and detailed questions we (I) can help somewhat but it is very difficult to diagnose over the internet.