Sounds like they are not so good anymore. There are YouTubes about how to test.
Also, did you dust it out and check fans for operation and if the spin freely?
I realize this is a very old DLP and see little to no discussion on it any longer. But before I give up and throw it away I thought i would at least ask. I recently starting having issues with the unit turning off. Usually changing the bulb has fixed the problem, but not this time. Now it still turns off the video, but sometimes the audio keeps going. I can see the lamp thru the back of the set is still on. Other times it does completely shut down. Sometimes with I turn it back on the video is shifted left and there is a vertical green bar down the right side of the screen. Turning the DLP off and on a few times usually corrects that problem. I am willing to try changing the board before I give up if people think these symptoms point to that. Thanks