Cambridge Soundworks SW310: static crackling sound when connecting/disconnecting

[AbydosBane]

I got an old Cambridge Soundworks SW310 2.1 system connected to my PC. It's probably around 17 or 18 years old and still working, however whenever I connect/disconnect it to/from my PC, move the tower or the subwoofer or put the whole lot on power after turning off everything, I hear static crackling, like a discharge.
I really got no experience with sound systems, so I'm wondering: Is this normal or should I worry about it? Can this crackling/discharge damage my PC? (I got two dead Motherboards in two years, for example, and start to wonder if it's just bad luck or if this might have something to do with it.)

If this is bad for my PC, it leads me to another question: What is a good replacement 2.1 system? Here I'm looking rather at a budget-model (max. 80 €), yet I don't want to spend money on something that's inferior to my actual Cambridge Soundworks system. Back in 1999 or so it must have cost something around 150 DM. Again, I'm rather a noob regarding sound systems, so all those informations I get when looking at a new model tell me fairly little.

For example, are these any good/better than my current system:

• 
  wavemaster MX3+ 2.1 System (50 Watt)
  Creative A250 2.1 Speaker System
  Logitech Z213 Speaker System
  Logitech Z313 2.1 speaker system
  Trust GXT 38 2.1

 

[americanaudiophile]

Could just be dirty contacts on the connectors. Won't hurt the PC.
Unplug the power supply before you disconnect cables and try cleaning the contacts.
You might be a spray product for the jacks.
DeOxit contact cleaner is very good.

 

[AbydosBane]

Could just be dirty contacts on the connectors. Won't hurt the PC.
Unplug the power supply before you disconnect cables and try cleaning the contacts.
You might be a spray product for the jacks.
DeOxit contact cleaner is very good.

Thanks for the answer. It's good to know that it won't hurt my PC. I have some Isopropyl alcohol at home, 70 %, I think. I'll try to clean the contacts with that and will see how it goes.