Can Dell repair the headphone noise in 6400's?

I've been talking to a dell guy because my hard drive decided to die on me early so i'm getting it replaced and i've said it to him about the static coming through the headphone socket when the system has the power adapter plugged in. He says that if I want he can organise for my laptop to be taken to a dell repair centre, here in Ireland or if I don't want them to look at the noise they can send out a techician to fix the drive on site. What I want to know is can dell actually repair this or is it a waste of time?

 

You may try to check first and see if the problem is hardware or software related, or related to an environmental factor. First of all, try the system on a different location and see if it is affected by another electrical appliance nearby. if you can still hear static, try using headphones and see if the static occurs. if yes, try another one. if it still happens, then the problem is with the system. if so, try updating the audio drivers, chipset drivers, and even the modem drivers. if the static still happens, try removing the modem. the modem is located at the bottom. if the static does not happen when the modem is removed, try putting it back and see if the static still happens. if yes, have the modem replaced. if the static still happens after the modem is removed, most likely it could be caused by the motherboard. it is best to have the system sent to the repair centre and have it checked.

hope this helps.