Annoying hum

[perplexed]

Hi

I have just switched to Sky from Freesat. We have a Sony analogue (i.e. not a flat screen LCD etc) TV and with freesat it used to hum with there was a bright area of white on the screen: we are getting the same problem with Sky. Is the hum being caused due to some problem between satellite broadcasting and analogue TVs?

Perplexed

[penrhyn]

I think you mean Freesat from Sky.
Check your SCART connection between the TV and your Sky box.
FYI, unless you have a Sky+HD box and are using an HDMI connection then the interface between the Sky box and the TV is analogue.

Blotches on your TV could be a sign that the tube is on its way out, or is possibly near a magnetic field, speakers or the like. try turning the set off at the wall and switching on again to trigger the deguassing circuit.

BTW Does the set receive analogue transmissions OK, or has your area switched.

[Kenedin]

For info:

How to Eliminate Hum or Buzz - eCoustics.com

[perplexed]

Thanks for the tips. I will try out the various suggestions in the article.
My area has been digital for over a year now.
The light area on the screen are not blotches but just light areas of the picture, for example, a hospital corridor, but it is when such light areas or scenes come on that the buzz starts.

[Old_nick]

Try the Freesat or Sky box with another TV. It could be the TV at fault.

[penrhyn]

When the set displays bright pictures the set pulls more current, what you are probably hearing the the line output transformer buzzing.
This is the component that generates the EHT voltage for the tube.
Might be time to repalce the set.

[MartinP]

The problem is caused by video levels that are too high for the TV Scart input. Try setting the Contrast lower in the Digibox Picture menu. Certainly sounds as if the TV is in need of attention but this might fix your symptom for a while. You could also try changing from "PAL" to "RGB" in the same menu screen.