HELP - External monitor of laptop flickers when power cable pluggedin

[ennioennioennio]

Hi,
I've got a Sony VAIO FE11H.
I've found this issue, wich is very annoying to me.
When i connect an external monitor to my laptop i get some horizontal
flickering: it only happens when the power cable of the laptop is
plugged in. When i disconnect the power cable of the laptop and it is
powered just by its batteries the flickering disappears instantly.

I've tried using a surge suppressor: no luck.
I've checked the ground of my electrical system, and it's okay.
I've tried connecting my laptop to a different external monitor in a
different electrical system: the problem persists.

So i think there's something wrong on my laptop.
Can anybody help me please?

 

[ennioennioennio]

Maybe it is ok on your system, but I don't think I would be plugging an

external monitor into my system while it was running.

I don't plug the external monitor while my system is running.
And i'd like to underline that it's only the external monitor that
flickers, and it doesn't matter when i plug it.

 

[GT]

Hi,
I've got a Sony VAIO FE11H.
I've found this issue, wich is very annoying to me.
When i connect an external monitor to my laptop i get some horizontal
flickering: it only happens when the power cable of the laptop is
plugged in. When i disconnect the power cable of the laptop and it is
powered just by its batteries the flickering disappears instantly.

I've tried using a surge suppressor: no luck.
I've checked the ground of my electrical system, and it's okay.
I've tried connecting my laptop to a different external monitor in a
different electrical system: the problem persists.

So i think there's something wrong on my laptop.
Can anybody help me please?

If you elliminate the mains versus battery element of this, it sounds like a
simple refresh rate problem. The laptop screen will be refreshing at 60Hz
(LCD), so it sounds like the external monitor is using the same refresh
rate. Plug in the external monitor, then right click on your desktop and
choose properties on the menu. In your settings tab, you should be able to
click on the picture and change the resolution and refresh rate of each
screen (may have to click on advanced for the refresh rate part). See if
that helps, if not then the interference points raised by others is more
likely. I would always try to elliminate the simplest thing first!