Dell Vostro 1510 Notebook PC - External monitor interference when using power adapter
I've got a Dell Vostro 1510 notebook PC here that I'm trying to use with an external 21.5" 16:9 Dell monitor. At least one other staff member is using the same hardware, as they all use a laptop/monitor combo, with their monitor set as the main display when plugged in [although the other staff member with the same hardware has the Nvidia graphics chipset instead of Intel in their 1510]. This laptop [Intel graphics chipset] is having some issues though. The user was mentioning horizontal lines going across their external monitor, faintly, but definitely visible and distracting. They weren't solid, they were moving, like they were caused by interference. The laptop itself was having absolutely no issues on its built in display, but when plugged into the external monitor via the laptops VGA port, the external monitor would show the flickering lines.
I did notice one interesting point. As soon as I unplug the power adapter from her laptop [a standard 90w Dell power adapter matching in volts/amps], the flickering on the external display stops. Instantly. If I plug the power adapter [or a 65w adapter] back in, the flickering resumes immediately. I doubt this is a driver configuration/version issue, and is probably hardware related, but I thought I'd run it by you guys to see if you have any tips to help get rid of this annoying issue, besides getting another laptop.