[xubuntu-users] Screen flicker on external screen with Radeon card

[István Abád Szarka]

Hi,

I am experiencing a horizontal screen flickr apparent with dark
backgrounds, but only on the external screen, with all refresh rates,
in most of the resolutions.
I tried it with different monitors and I have it on all of them. So
far I have only tried the VGA connection.
The strange thing is that the flickr gets stronger if the HDD is
working or if the CPU usage is increased.

I could not really find any solution to this so far, does anybody have
any suggestion?

Technical information:
    Ubuntu 14.04.2 LTS
    3.13.0-51-generic #84-Ubuntu SMP Wed Apr 15 12:08:34 UTC 2015 x86_64
    [AMD/ATI] RV620/M82 [Mobility Radeon HD 3450/3470] (prog-if 00
[VGA controller])
    Kernel driver in use: radeon

Thanks,
Istvan