HTPC Whining noise when laptop connected to TV

When I use a 3.5mm audio cable to connect my laptop to my TV, I get a nasty whining from the TV's speakers when the laptop's fan spins. What can I do to stop this (other than unplugging the cable)?

 

Use an RF shielded cable or a ferrite ring (available from maplin) to remove the noise. It may be too strong though and affect the soundcard directly.

 

Or internally like it is in mine... The power leads on the motherboard interfere with those from the sound card. Quite annoying...

 

Is there any performance difference between rings and clip-ons? Should be easier to get a snug fit with a clip-on I think.

If that was the case, wouldn't if affect the laptop's internal speakers as well?

 

The rings allow you to filter out more interference with more loops. Clip-ons may be OK.

The internal speaker normally goes via a trace on the board to the plug and can be less succeptible to interefence due to the small size.

From my physics knowledge (forgetting it quickly) it's only items which are the same scale size as the wavelength that get affected. So it could be the 3.5mm jack is the wrong size and can get affected.

 

Thanks. A Maplins store recently open nearby, I'll get something on the way home.