Some video files i try to play off of my external hard drive through the USB port have white lines through the picture. How do i get rid of them?

This is probably due to improper detection of external Hard Drive. Als checkout your USB Port.

Depends upon the type of lines you are referring to. Sometimes these "lines" are scrambling signals that are inserted as part of DRM (digital rights management) software. Unless you have received the DRM code for the particular video clip, you will not be able to view it clearly. It is an anti-piracy, anti-copying method and works quite well.

The TV should support the file system to read the directory structure of the Hard disk and also the the file type to read the video file. Try mpeg / jpeg file on a thumb drive on the same USB port.

The TV needs the drive to be formatted in a certain way before it can be recognised. Also, the file types the TV will play are specified in the User Manual.

The supported formatting for the USB port is FAT12, FAT16 and FAT32. It is FAT32 that you are able to format in from a Windows PC.

The video file format that the TV supports is DivX.

There's no specific mention of the TV having support for USB disc drives, but it does say it supports USB Mass Storage Class devices. This does include external hard drives. As a general recommendation, use an external power supply with the drive rather than relying on the 5V USB power rails.

Sounds like the video file didn't copy correctly. Try and copy the file again and then try to play it again.

Your TV is very unlikely to be able to read the external drive. The USB connection on most TVs are meant to view pictures and lack the ability to navigate file systems and read most file formats. Your best bet is hook the hard drive up to a computer or a video game system (PS3 and Xbox360 do this) and then hook that computer or game system to the TV.

I have tested the LA40C530 Samsung with a 300GB external hard disk and it works well without any issue. My guess is that it should support 500GB as well. I have played video/music/pictures on my WD 300GB HDD.

USB stick has to be formated in FAT32 file system.
Some players will only play sticks up to 2 Gigs, some may recognize and play video files even from external hard drives.
Aveis is a no name player, so who knows if it'll play anything besides MP3 and JPG.

I'd go with a Pioneer or Coby (both at Best Buy); both play DivX format from sticks and external hard drives; no MPEG-4 or MKV files though, which is a bummer (did not find any player under $100 that does.)
I tried them both (also tried Philips and Toshiba), but the Pioneer had far the best picture and sound amongst all of them. Coby was OK, but the display broke.

Might be video card problem or something that is connected with your video is getting fault, dirty or loose contact is a big candidate. If you can test it using external monitor if it have external monitor port try that first. If external monitor works then back up your files immediately using external media. CD, dvd, flash drive or in another external hard drive.

Second option is to take out the hard drive and hook it into a USB hard drive adapter or a USB enclosure. And retrieve your files if you want on another working computer.

Then the laptop should go to a repair. If you are not so sure of doing this, have your friends that have knowledge on this assist you or bring it to a reputable shop.

Just for an input.