Firstly plug a set of headphones into your computer to test it is not faulty.
If the sound is ok in your headphones then your speaker system is faulty,,,,they do click when switched on, this can happen whether faulty or not.
If you do have sound through your headphones check all of your cables for damage etc. if it still does not work it is cheaper to buy some new speakers rather than pay to have them repaired.
If you have no noise from your headphones contact me again for further info.
Cheers Ray