The Voltage and Amp Rating need to match with voltage more important than A or mA rating, however the rating should be greater in amp rating than the laptop requires to avoid damage to power supply. If the A or mA rating is lesser on the power supply than the laptop needs it can cook the power supply making it very hot and possible failure or fire.
If you plug in the wrong voltage you can smoke it. Wrong amperage and you can smoke the power supply itself.
That being said, I have a Gateway Laptop that I am using a HP charger with. The voltage is an exact match and the amperage rating is also within 200mA. I had to chop the end off the gateway power supply and add it tot he end of the HP power supply to make this work though as for the plugs are different.
Its best to use the power supply intended for that model.
For the fact that you dont have any lights it means that its either wrong voltage and maybe cooked, the amp rating listed as amps or thousands of mA is too weak to carry the load of the larger laptop ( possible since you stated the power supply does to a netbook which likely draws 2x to 4x less amperage than the laptop needs ), the plug goes in but center pin not properly connecting for (+) connection ( there are some with smaller pins and others with larger pins for (+), or the laptop is damaged internally or at the power jack to where there is an open circuit.
I'd look up the make/model and see what the amp and voltage rating is if not listed on the bottom of laptop on the mfr label. And you could cook your netbook power supply by it connected to a system unintended for it that pulls too heavy of a current (amp draw).
