Q:
Hello, I have an Acer 4200 laptop, now its power faucet is broken. And the power adapter could not supply power at all on it. Can you tell me how to fix it up or could I change it? And what about the repair cost? Hope your suggestion and help, thank you so much!
A:
1): Problem like yours, generally, is caused because power adapter’s loading voltage is not stable. If you have a multimeter at hand, then you could test the voltage in empty loading state. Or you could buy a new power adapter, don’t worry whether the power would get the entire computer scrapped, as there’s power protection circuitry inside laptop, and only improper usage would cause damage to the computer. You could install SpeedFan to test the temperatures of motherboard, hard disk and graphic card, and to ensure whether the motherboard has an overheating problem.
2): If the power faucet connected the motherboard is badly soldered, and you have a good DIY ability, then do it yourself. Take apart the laptop, check up the soldering spot of power faucet, whether it’s loose or not. If yes, solder the electric iron, if you don’t think you could manage this, then send it to repair. Generally, the repair cost would not be much, just about 100 dollars.
 And another possibility is that the copper cable inside the connection cable of power is broken, find out the broken part, take it apart and reconnect it.