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Thanks for the question. My name is Dan.
Fan #2 should be the lamp exhaust fan. Pretty easy to get to. You'll need to remove the TV's lower rear panel, then stand behind the TV. On the left you'll see the electrical chassis, and you'll see the optical block on the right. Right away you'll see fan #1 on the DMD board (metal case with holes in it). The lamp fan is nearby, on the same main assy. See my picture.
Now first you'll want to remove the rear panel and hold down the door switch (see picture). With that switch held down, turn the TV on. Make sure fan #1 on that metal case spin up OK. Not jerky. Make sure it's smooth and fast. It probably will be. If that fan is fine, go ahead and replace fan 2. If fan 1 is jerky or static, let me know because you might have a bigger problem.
Fan 2 part number is XXXXX You can get one from about a million places on the web.