COMPAQ Presario R4012US laptop ac adapter replacement

This COMPAQ Presario R4012US laptop ac adapter is rigorously tested, meets or exceeds original COMPAQ Presario R4012US laptop ac adapter's specifications, brand new with 1 year warranty.

(a) Before ordering this replacement COMPAQ Presario R4012US ac adapter, you MUST check your laptop's input voltage and your original ac adapter's output voltage. This replacement ac adapter must have same output voltage as your original ac adapter's. Using adapter with wrong output voltage will damage your laptop.

(b) You can calculate your original COMPAQ Presario R4012US ac adapter's output Wattage [W] by multiplying the Ouput Voltage [V] by output current [Amps]. i.e 19V X 4.74A = 90 Watts. You can choose a replacement ac adapter which has higher Amps than your original ac adapter's; but you can not choose an ac adapter which has lower Amps than your original ac adapter's because it can not provide sufficient power to your laptop. Adapters with higher Amps will not damage your laptop. The adapter's output current (Amps) and output power (watts) are maximum load ratings. Computers only draw as many amperes or watts as they need. The computer needs low current when you are editing files or writing emails. The computer needs high current when you are running discs or seeing a film. The COMPAQ Presario R4012US ac adapter does not work with maximum current mostly.

(c) Please carefully check the plug tip's size of the adapter to make sure it can fit into your computer. First of all, please make sure that your original adapter's part number and your laptop's model number are listed below.

Click here for tips on COMPAQ Presario R4012US ac adapter care and on how to find out your laptop's intput voltage and original ac adapter's output voltage.