inspiron 6400 on external monitor, regions of image flash

Hi, all,

I have been using an external LCD monitor hooked to my inspiron 6400 for 6 months, everything is fine. but 2 days ago when I moved the laptop a little far away from its old place, I tried to add a 6-feet VGA extension cable to the present VGA cable of the external monitor . the image with extension cable is horrible, so I take the extension cable off and move the laptop back to the old place. and a problem showed up:

when I hook my inspiron 6400 to the external LCD monitor via VGA port on the laptop, some regions of the image on the external monitor flash (if I put on a document, the words are shaking, or "dancing"), for example the upper right corner, and the middle section of the screen are doing this right now. and if I take the VGA cable off and put it back on, the flashing region changes. but one thing for sure: Not all the screen flash, only several regions.

if I only use the own LCD of the inspiron 6400, everything is fine.

what is the cause of this problem? is this a contact problem between the VGA cable to the VGA port on the inspiron? or is this a video card problem, like driver is too old?

by the way, I hooked the same external LCD monitor to my old dell Latitude CPx laptop, the image is fine (sure at a lower resolution, Cpx is an old laptop). the image are stable.





thanks,

t.z.

 

Never had the symptoms you're describing. The only issues I had with external monitors was that I would see both screen flash garbage for an instant every so often. No dancing. Maybe you have a sync issue?

 

hi, guys,
I just lower the external monitor resolution to 1280x1024, and the flash gone. the normal setting for my external LCD is 1920x1080. and then tried on another LCD external monitor, same thing , no flash at low resolution, like 1280x1024, but will flash at 1650x1050. will this information helps?

 

Sorry, never hooked up an external monitor beyond 1280x1024 res, so I don't know whether it's outside the range.