Dell M4700 video acts odd at boot (moving colored lines)

[barleysinger]

Every so often I see odd changing lines of color on the upper area of the screen. After a full reboot It is usualy gone. If not, it is gone after I've logged in. ONCE the issue persisted for a few seconds (maybe 10 to 15 secs) after logging in. This is odd. I went to the dell site, & downloaded and ran their full system diagnosic with no issues... so there doesn't seem to be a detectable driver issue, obvious flaw in the onboard graphics control chips, or the internal card - as one would hope a diagnostic would check them. Bad ram ought to effect the machine in other ways too. Puzzling.

 

[smorizio]

bad gpu memory or bad gpu chip or power can cause those issue. first i would pull the gpu with the power off make sure the card still locked in. there are 3 party gpu memtets programs out there google for them. run them see if any of the ram is bad on the gpu. the other issue as it a laptop can be the inverter or the lcd screen. if the unit out of warranty i would wait till the screen or part failed where the issue there in windows. if it is if using an ext monitor is fine then the issue is the screen.