Monitor started going to black screen randomly, Then it just kept getting worse. Now it comes on for a few seconds and go`s black after a few seconds. Note blue light in power button stays on while this happens so it is getting power to it. LCD has a internal power supply. Mine is the black version.

See video here:
E550i B2 blacked out screen VIZIO NO PICTURE HAS SOUND FLASHLIGHT TEST

Hope this helps.... Your monitor has an inverter issue. You know it's an inverter problem when:
1. Your monitor starts normally and displays the startup/desktop screen for a while.
2. Then it suddenly goes off, leaving a blank (black) screen or a very dim display.

To fix this black screen problem, change the inverter board (based on your monitor brand). Source(s): http://lcdmonitorrepair.annics.com

There are 4 c5707/5706 in the inverter transformer driving circuits, the cause of the problem was due to poor solder connection in the bias circuits of the transistors. Make sure to check that after you install the new transistors otherwise you will blowthem up. Common problem with this model. When the circuit drwas too much power from the power supply, it will shut itself off to ptotect itself.

Ours is crapping out just like yours. Picture goes out, "black and white squiggles" appear in the top left of the screen then TV input appears, then it either repeats or gives me my picture back. This happens with both the HDMI slots (tested all 3) and both Component slots. Seems like the bulb or a circuit board on the TV is faulty. What a piece of ****, never spending another dime on LG products. I did get it to come back by hitting the back of the TV with a good slap, but it gets really annoying.

Sounds like a bad solder joint on the printed circuit board. Once it heats up then it no longer makes good contact and the monitor goes black until it cools down and makes contact again. You could resolder it if you knew where it was but monitors are dangerous to go playing around with as they can hold very high charges of electricity in their capacitors that are very dangerous. It's a throw away world. Go buy a new one.

I've experienced the same problem in a large environment and found that capacitors within the pc itself were swollen...replacing the motherboard solved the issue.

Your circutboard is fried. You need to have it replaced.

If this helps at all, please rate this as a FixYa. - Evolution

Have you noticed if the monitor gets hot before it turns off?

Please, don't open a monitor and try to repair it yourself. It can be very dangerous and it's not worth getting injured.

Well, this problem is going to only get worse. You can probably send it back to the manufacturer if you still have a warantee, but if you can't just buy a new monitor.

This is most probably cause by one or more Faulty Electrolytic Capacitors, I find these are the MOST commonest form of "Fault" in these LCD's TFT's units. I ususally simply replace "On Spec" all High Value Electros, in fact ALL Electro's are suspect and often I just "Shotgun" and replace 'em all. Usually fixes all problems. Always use High Temperature Caps.