Lamp and temp lights flashing

SOURCE: t.v. will not turn on. flahes "lamp" then no picture!

I have a picture but the tv will periodically turn itself off during the day and then flash the 3 blinking lights...anyone know what the problem could be. We can fix it ourselves if we knew for sure what it is.

SOURCE: TV won't stay on. Green & Red light timer-lamp (Green) stand by/temp (red) flash.

Most likely needs a new lamp. Easily done yourself.

SOURCE: Have replaced Lamp and still does same thing.

I replaced the ballast, a solution not even mentioned by the 3 Experts I was referred to.

SOURCE: Samsung HLN467W 46 in. Rear Projection HDTV

I would suggest replacing the Lamp

SOURCE: Samsung DLS not working(with new lamp)

The grinding sound is most likely the color wheel. The lamp will not fire up if the computer senses the color wheel is not in motion or turning too slowly. It does this to protect the color wheel from being burned.
Something else you need to realize is the fans sometimes make some noise(especially the fan at the rear of the DMD Board).
The Ballast does not go bad that often and is misdiagnosed more times than it actually needs to be replaced. Sometimes the DMD Board is defective and won't send the color wheel the signal to start which in turn doesn't let the lamp turn on. I have read this misdiagnosed as a bad lamp, ballast, and color wheel multiple times. I currently have two of these in my shop at the moment and they were both verified by swapping known good DMD Boards.
There is some very good information available on this site but many times it isn't that simple of a repair. You need to get all the information and verify before buying parts. Most of the time it will pay for someone to have a reputable shop do a repair rather than buy parts that are not needed. I have had three people buy lamps in the last week, and two replace capacitors, only to give me a call and fix the problem correctly. All of these people got the repair tips from the internet.