Dell Xps 17 L702x right speaker hissing noise + sometimes it loses volume? what is the problem?

Hello Jimco

thanks for the useful information. I am not 100% certain if its the software/hardware so I will probably wait until 2-3 days and get back to you. I would like to  ask, is it hard to change the speakers or what procedure does it involve 

You can download the "Service Manual" from the XPS L702x documents page. I use Adobe Reader to read the pdf manuals instead of my browser -- it is easier. I mean that when I click on the link to the Service Manual my browser(Firefox) will open it in a new tab, but then I re-open it with the Adobe Reader program. There is a button on my browser to do that. In the Adobe Reader program I use the "save as" feature to save the manual in my laptop.

The manual explains step-by-step how to dismantle your laptop. On page 133 of the manual there is a section named "Removing the Speakers". There are 7 steps, but one of those steps is to remove the system board.

When you look at the instructions for doing that on page 127, you see that you have to dismantle just about the entire laptop in order to replace the speakers. That is actually not a hard project if you can use a screw driver and are organized enough to keep track of the screws as you remove them. There is nothing technical involved, but there may be some cables that you have to unplug and it might require a little common sense to examine the plugs to see if there are any clasps or such that you have to release before just yanking on the plug. That sort of thing. The whole process of dis-assembling and re-assembling can take some time but is pretty straight-forward and every step is explained. It would be helpful to do it in front of another computer where you can see the manual while working on your laptop.

I have dismantled a few laptops but not an XPS L702x so I can't provide anything specific to look out for on that particular model.

Hi Jimco

I believe the right speakers are actually faulty as I tried everything  and I noticed the price to replace the part of the speakers cost as much as external speakers which I might just get. I don't want to dismantle the laptop because it might cause more problem.

I didn't notice this before but one of my headphone jack is loose,for example if I plug my headphones into the jack,you don't require any force at all to stick it in and out. The s/pdif jack is working fine. I also noticed when restarting the laptop, the speaker will work normally until the next day when I turn the laptop back on 

Yeah I might get an extended warranty but I might wait for 1-2 years and then get a new laptop + purchasing warranty with dell. Thank you Jimco for assisting my help