I suspect the replacement lamp you first put in. It shouldn't be shutting off like that. I dont know if the replacement ballast was correct, but I wouldnt buy parts off of Ebay unless I knew it was an oem part.
put the old ballast back in and see if it works intermittently again. That should answer the compatibility question.
I dont know if those parts are interchangable or not. You might try a little investigating at wehaveparts.com
WARNING: Before doing any work on your television, make sure that it is unplugged and has not been in operation for more than 1 hour to allow the lamp to cool down. Use extra caution when working on a power supply, like the ballast in this topic. Even when the television is unplugged, do not touch the electronics within the device. Capacitors can maintain a charge and cause a shock.
What is the ballast
An electronic ballast is a device that provides steady electical current for the starting up and operation of a lamp.
When to Replace the Ballast
If your lamp is not starting up and you are confident that the lamp is good (e.g., it is new), it could be a faulty ballast.
Where to Buyhttp://www.statewideapp.com.au/index.php?selectedContent=1188381775
I have had good experience with Partstore.com in getting replacement parts for my electronics repair projects.
How to Replace the Ballast
Compared to other parts in the LG television, the ballast is relatively easy to access.
Remove the back panel from the television.
Remove the lamp.
Unscrew the cover sensor switch on the right side. The wire going to this switch is short and will prevent the insides of the television from sliding out.
Locate the ballast. It is on the right side (facing the back of the set), mounted on top of the large cooling fan. The ballast has 4 screws holding it in place, one on each corner of the green circuit board. It also has a red two-wire power cable that goes to the lamp connector not far away. Take careful note of the position of the cables and how the plug is connected.
Unscrew the lamp connector. It is easier to access the screws when it is in its normal position and before the insides of the television set are loosened. There are two small brass screws that must be removed.
Here is the connector when attached.
After removing the screws, the connector will come free:
Remove the screws holding in the 'guts' of the television. This will loosen the entire inside of the television allowing you to slide it out. You may find it useful to follow steps 1-6 on this guide to replacing the LG color wheel. Accessing the color wheel requires that the insides come out fully, so some wires need to be disconnected. To access the ballast, you should not need to remove any wires. Stop at that point in the color wheel instructions.
Carefully slide out the right side of the inside unit. Unless you removed the screws that hold the left and right panels together, the entire unit will move as one piece. At first, you'll have to ease out the top and bottom center of the unit as it is a snug fit. Once they are free, you can slide out the right side just enough to access the ballast. You should not need to remove any cables to get the insides out enough to work on the ballast.
Use caution to not touch the electronics. This is a power supply and the capacitors can hold a charge even when the television is unplugged. Unscrew the ballast circuit board and remove it. The power cables should already be free. Store the ballast in a safe location.
Install the new ballast in place of the old one. Snake the red power cables through the holders. Like on the removal, it may be easier to screw in the lamp connector plug screws after the insides of the set are secured back in place.
Put the insides of the television back in on its track and screw it in. Be sure not to put any screws in to holes that are to be used in fastening the back panel. It helps to compare the back panel to the back of the set to determine which screws are on the inside vs. the outside.
Reattach the cover sensor switch from step 3.
If you haven't done so already, reattach the plug at the end of the red cables. There may be a plastic holder that you need to remove from the old ballast that the screws go into. The plug fits into this piece a bit like a puzzle, so it may take a little wiggling to get it out. Be careful with this. I've heard from at least one person that this plastic piece is brittle and can break.
Install the lamp.
Put the back cover back on and fasten with screws (14 screws).
Plug in the television, say a prayer, and turn it on.
Have you replaced the ballast in your DLP television? Tell us about it.