I have a LG 32LD350 which is like 1.5 yrs old. when i turn it on the screen is all black, but then after like 5mins. there come the picture but it has a white horizontal line across the screen. then it flicker part of the time, what could be the problem?

The LCD has quit working and the screen is no longer working for your TV.It would be more easier to purchase a new TV than to try and fix the TV that you have that is broken.

Time to get a new one

The inverter needs replacement. You should be able to get one from www.tvrepairworld.com

Sounds like a blown capacitor on your board to me. Its a common problem in Samsung TV's and is typically an easy fix, but I think in the LG's its a bit more expense and not as easy as swapping out a Capacitor. I think the main board may have to be replaced there. What actually happens is the capacitor bursts at the top and oozes liquid that solidifies, its caused when the capacitor that is used is underrated for the application (basically some engineer's solution to making us have to buy a new tv in 3-4 years, a slightly underrated capacitor will have a shelf life of use, kind of like a timer, they all do it belive me) eventually the set will not rendure any picture at all and the board will have to be replaced.

Probably something wrong with the lamp. Buy a replacement.

Most a likely a problem with your Y-Sustain board which will then not drive the screen giving a black picture. The fuse on the board may be open circuit & need replaced but most likely you will need to have the sustain board replaced.

a failing video board

You have the picture in picture on and the second picture is black because there is no input source plugged into the second input.

In your manual, look up the picture in picture functions and how to control them. you should also be able to change that second picture to see the main feed and swap between them.

Good Luck,
Charles

If the Video (Picture/Pix) is gone but you can hear the Audio (sound), then it could mean the YSUS PCB Assembly is gone/kaput/finish. Can replace the PCB, not repair the PCB due to timing circuitry involve. Cost maybe roughly $500 depending where you located. The PCB is located on the left hand side of your TV when you are facing the back (Back open). Might find 3-4 brown flex membrane connecting to the plasma panel. The PCB has a silver or black aluminum heatsink (big) on it.
Good Luck.