New telly has 'dark' screen

[Halb]

My dad bought my mum a new telly for XMas, nice big 40odd inch JVC. They have plugged it into the sky box via the scart lead that they used on the old one. The picture is 'dark'. This is not to do with the contrast et al settings.
It is most noticeable on the sky TV Guide screen. I notice that when I plug in the scart lead for a fleeting moment the screen looks normal and is bright, it then flicks to the 'dark' version.
Tried two different scart leads, same issue.

Any help or advice?

[Muntu]

See if you can find some sort of "Picture mode" in the settings, there may be different brightness settings for 'cinema', 'sport', games etc?

[V8LM]

Try changing the video output to RGB on the Sky box if it is not already: Services / System Setup (4) / Picture (1) / Video output

[TonyRPH]

I bet the auto power save is enabled, which forcibly reduces screen brightness to conserve energy.

OP, if you told us which model it is - that would help.

[B17NNS]

Have you tried using an HDMI source instead of the scart?

[P700DEE]

My 2C is Power save mode