occasional loss of signal to an external display

[Marin85]

Hi,

I have recently started experiencing complete loss of image when connected to a certain external display. In some cases when I try to connect to the external display, it just remains black. However, if one looks carefully in the external display, one can notice that the backlights activate and one can also see very tiny lines of noise passing through the display. It seems like windows successfully delivers a signal to switch to the external display, but my desktop does not appear on it. In other cases, the external display mysteriously goes black, with the same observations as above, while connected to my laptop, and when this happens, in some very rare cases it successfully "resumes" back to showing my desktop. But as a rule, it remains black. The problem occurs in every display mode (i.e. only projector, extended, duplicate).

I have also tried to boot up with the external display attached to the ThinkPad. Same thing happens (when it happens), nothing is displayed, not even the ThinkPad logo and once again one can notice the change in the backlights of the external monitor as well as the white tiny noise lines.

However, the external display works attached to a desktop without any issues whatsoever. Unfortunately, I don´t have another external display at my disposal to test it with my laptop. I don´t remember the exact model of the external display, but if you think it´s important, I could dig it out. Apart from that, here are my specs:

laptop: as in my signature
OS: Windows 7 x86
driver: the one provided via Windows update
software: no presentation software, I am using the built-in windows feature to switch between displays.

There is also an alternative desktop Radeon driver that can be installed (and seems to work fine), but I haven´t tried it against this issue yet. I will try it tomorrow (if the driver really works).

Any help is greatly appreciated!

Marin

EDIT: I forgot to mention that there also times when the external display works fine, connected to my laptop.

[Harryc]

What happens if you run a Linux Live CD for awhile?

[Marin85]

Thanks for your reply, Harry! Actually, I haven´t run the LiveCD yet, because I tested today the other driver I had in mind, and the external display has been working stable all day, so I could not reproduce the issue (under Windows). I don´t know if it is just a lucky day or the problem was really with the driver, but it looks primising so far. The only concern seems to be the fact that in some cases the external display did not show anything while the laptop was rebooting. I think I should go ahead tomorrow following your advice with the LiveCD and see if the external display still behaves stable and post back.

Update: I did not experience yesteday any issues with the external display under Ubuntu LiveCD whatsoever.