Compag nx 7400 my laptop power supply not work what hepent?

Whenyou connect the power adapter into the laptop, does the power LED light up? Ifnot then - The battery adapter or the adapter's power lead or the laptop's powersocket could be faulty. Check power adapter's DCplug that connects into the laptop power socket with a multi-meter, the voltageshould be slightly higher than the voltage that is printed on the label on thebottom of the adapter. If the voltage is zero or way below the voltage that isprinted on the label then the power adapter is faulty and needs to be replaced. If the adapter is OK thenconnect it to the laptop and power it up, then look at the power/batterycharging LED light and wriggle the power plug in the laptop's power socket.If the power/battery LED light flashes and in a certain position this LED lightstays firm, then the power socket is either faulty or it has a dry solder jointwhere it is connected to the motherboard. This can be repaired but itrequires the laptop to be completely dismantled to get at this power socket andrepair. If you cannot DIY then I suggest you get a quote first.