I'm sorry to hear that you're having this issue. You've listed quite a history on your set.
Unfortunately, I don't have the ability to diagnose a unit without first inspecting it. Even with the detail presented here, it's difficult to determine if the "whirring" sound is normal for a wheel that spins as fast as it does. I might compare it to a hard-drive sound, but even then, it's hard to determine if it's normal or not.
While I don't want to offer one-over-the-other and risk you spending money on a part that leaves you in the same position as you are now, I might recommend letting a technician take a look and see what the issue might be.
That said, I'll be happy to bump this thread up to see if anyone else might be able to offer a suggestion.
Model#: HL-T4675Sx Age:3+yrs
Three years after owning the TV, the TV would not turn on. Noticed the three blinking front light cycle, and read that the problem was most likely a lamp replacement issue from the Tech Manual. I replaced the lamp and all worked fine for a little over a month, then the same issue happened.
Replaced the first replacement, and the TV would not turn on. By this time I began to hear a slight whirling, but not "grinding" or high-pitched by any means, noise coming from the rear. You can really only hear a whirling when your head is behind the TV. Also, the TV would immediately begin it's power up cycle upon plugging in the TV. I had to keep the TV unplugged for fear it would try to turn itself on. The lamp does not fire up.
Replaced the balast. Same issue. Same small whirling sound. Removed the lamp housing and seen the color wheel is spinning, which is what I linked the whirling noise to. It is not the fans as I removed the back cover and placed my ear next to the back. When I got close initially, my hand brushed the large, rear fan and that had appeared to turn the TV off. Unsure whether or not that was during it's "Powering Up Cycle" or not, so unsure whether it was to blame. But now I can plug in the TV and it will not try to power up until I manually turn it on. Still makes whirling noise.
Received a new Color Wheel with housing. I seperated the old color wheel (which had NO apparent wear or tear at all) from the original housing and swapped it with the new color wheel. Plugged it back in and turned on. Same whirling sound and still, absolutely no picture, no lamp power, do receive a click from the balast, and the color wheel does begin to spin.
I am lost right now. I have no idea what next. The only two items I can think of is either: 1. color wheel housing or 2. DMB. I do not want to be spending $250-300 for this board. Is there any way that the color wheel housing could be the reason why the color wheel is making this whirling noise.
"Whirling" - the spinning sounds like it is spinning quickly, but the pitch goes from a very low to a low high tone. Meaning when I hear it, the noise sounds like the disc is spinning off-center or unevenly. Does that make sense?
Can someone please, please help me. I've pumped a decent amount of money into this TV already, and am coming up with nothing.
Thank you for anyone who can help me out!