Here's question from a pained Samsung HLP5063WX DLP television owner,
"I have a Samsung DLP TV model No. HLP5063WX/XAA. About six weeks ago it started to hum for a few minutes during warmup, but would get quiet after a minute or two. Now, it makes an obvious fan rubbing sound for a few minutes before quieting down. There are no warning messages. Should I pull off the cover and inspect the cooling fans (for cleaning or lubrication) before I order any parts or should I order one of the fans for replacement. I am handy with tools and good at fixing things, and I have no problem with taking it apart and putting it back together twice."
A fan problem it isn't a bad guess, but it likely isn't the problem with your telelvision. The most likely scenario is that your color wheel is dying and needs a replacement as these are notably defective.
How to tell if this is a fan or the color wheel?
Taking off the back cover is a great way to see if the fans are making the noise. It's also a great way to get hurt, so be very careful! There is a toggle switch that prevents the TV from turning on, so you'll have to bypass that by taping it in the closed position.
If you can see the fans, great. I think you'll find that the sound you're hearing doesn't come from the fans, or sync up with their operation.
Once you're convinced it is the color wheel, read these posts for information on how to replace it. It's not that tough!
Good luck and let us know how it turns out.