Is that an HP laptop, they are known for it. If all else fails try this lot. Laptop Adapter, Buy Laptop Charger, Online Laptop Chargers Prices in UKBastard gets me like that all the time. Can spend days tearing the house apart trying to find what it is I am looking for. Give up in the end and go out to buy another one only to find the original one upon my return from the shops, sitting in some obvious spot like in the middle of my workbench
Currently looking for a laptop charger with an odd voltage that none of my universal supplies handle. I'm not giving in this time though.