Hi Tigga, it sounds as if it's likely the color wheel. Just some thoughts: have you tried holding a piece of hose to your ear and probing around, as auto mechanics do to pinpoint noises? Just to make sure it's not the fan you installed (or to check out the one you removed), you could power up the fan outside the TV and see if it's quiet. A while back I measured 7.2V of drive voltage on one of my fans, and they're rated at 12V, so if you apply voltage within that range you could see if it spins quietly. I don't recall which wires had the drive voltage and which one was the tach feedback, but would guess that red is +, blue is -, and yellow is tach. I'd first do a quick check on a fan in my TV with a voltmeter to be sure. You're right that the TV will shut down if it does not detect a spinning fan. These TVs use the tach output as feedback to adjust the drive voltage to keep the RPMs at 1200.
Hi Dave, sorry that I missed your offer of your main board. Up to about 3 weeks ago I was checking the forum regularly, but stopped because kwarner
was kind enough to offer his main board. (You're right--email notifications of forum traffic are spotty at best!) His board is installed and working great! Thanks to both of you! Now I have to dig into my old one and see if I can find a burned up part. Yes I'm a geek.