Reply
Member
dinchan
Posts: 2
Accepted Solution

Horizontal lines/flickering on monitor when laptop is on AC power

Computer info:
Laptop, Toshiba Satellite A100
OS: Windows XP, 7
2GB RAM
Intel Duo Core 1.6Ghz

Monitor Info:
Samsung 2243SWX LCD Monitor
Connection: VGA

The issue:
I just bought the above monitor for use with my laptop. Everything works great except for one thing. When the laptop is plugged in to AC power there are horizontal lines running up and down the screen. Sometimes it gets worse and the sides of windows open on the screen, and text become jittery & jagged looking.

If the laptop is running on battery power the image on the monitor is perfectly fine.

I have tried the laptop with different monitors, and the same thing happens. I have also tried the monitor with different computers and it works just fine, leading me to assume the issue is with the laptop itself. Thinking it might be interference of some sort I've also tried a heavy duty shielded VGA cable, a different AC power cord, and different wall outlets, all with no improvement.

I can't think of anything else to try short of taking it to a Toshiba service place to have it looked at, but I'd rather not have to pay that much money on a 3 year old laptop.

Any ideas/suggestions/help would be appreciated!

Member
dinchan
Posts: 2

Re: Horizontal lines/flickering on monitor when laptop is on AC power

Ended up being a ground-loop issue. Fixed by ungrounding one of the power cables (didn't matter whether it was the laptop or monitor) as shown here: http://mrgnome.wordpress.com/2009/06/12/external-monitor-flicker-laptop-ground-loop-problem-solved/