NEC Fan Noise

[redsharkwon]

I just bought the NEC 50XR4 all in all a fantastic picture. My one small complaint is that the Fan noise from the unit is quite audible even at 12' viewing distance. Does anyone else have this issue?

[ryaron]

I have the same unit. No fan noise what so ever from viewing distance.
I'm sensative to fan noise and once even returneda Motorola DVR because of fan noise.

I'm very happy with the NEC 50XR4 but noticed that it has very noticeable image retention. It goes away after a while but it's a bit disturbing. I also have a NEC 42MP3 and it shows non of that.

[redsharkwon]

Interesting - then I wonder if my unit has a bad fan. In addition when it first turns on it is quite loud, similar to when you first turn on a computer, then it quiets somewhat to the level that I can hear while viewing.

[slopo2]

I too have the 50XR4 and have an audible fan noise at 12', plus noticable image retention. The fan noise is masked by normal speaker volume, and the image retention does go away after a while. 30 seconds of screen inverse or white helps to quickly eliminate the image retention.

[dgsowers]

Check out the following thread where I have described the same problem. Read for a few pages as others have experienced the loud fan.

Click here for other post (http://www.avsforum.com/avs-vb/showthread.php?postid=4926384#post4926384)

The following is the begining of the discussion of the fan:
The fan is very noticeable in my setup. I don't know if the wood walls vs. drywall causes the sound to reflect more (probably a stretch here). I have considered calling NEC to see if it is normal.

What type of fan noise are other people hearing? I know this sounds weird, but mine is not the sound of air, not the soft hum of a motor. It sounds like the fan blade is hitting something. You know the sound of a playing card on the spokes of your bicycle. Similar sound, although not quite the intensity of the fan blade actually hitting something. More the sound if you were to say rrrmmmm rrrmmm to your kid mimicking a motor sound. I can hear it with the sound low or in between dialog if the break in conversation is long enough.

[overtime]

I can clearly hear the fan at 12' if I have the sound muted and the house is quiet. Its very subdued and doesn't bother me but if someone is sensitive to such things then I could see it being bothersome.

The XR4 is mounted to the wall (drywall) and the room is heavily carpeted (family room).

overtime

[redsharkwon]

Well sounds like the noise is fairly evident for most XR4 owners. Has anyone tried sound dampening material behind the plasma to absorb some of the sound. I have mine mounted on a brick fireplace so not much absorption going on there. Againl, love the set just a bit annoyed by the sound.

[flamedog]

Just fired up my 42XM3 for the first time Friday evening. After it had been on for about 2 or 3 hours...while I was adjusting settings, comparing different inputs, etc. the set went into "takeoff" mode--the fan(s) cranked up to high (like someone mentioned when you first turn the unit on). They stayed that way. I flipped through the manual to see that there is an overheating mode where the fans kick into high. Yet in my case, there was plenty of ventilation, no excess heat was apparent. So after about 10 minutes of waiting to see if they would drop back down to the normal level...they didn't...I switched the set off. Waited 10 seconds or so and turned it back on....everything was normal. Have logged about 20 more hours and this has not recurred. I'm guessing perhaps it was just a fluke of the sensors during their breaking in period.

The normal volume of the two (I think that's all I saw during installation) fans is quite acceptable to me even though my set is in an armoire that would seem to do very little to mute the sound--if anything it would amplify the sound. But I would say this...I have built many custom PC's and have paid a lot of attention to various fans and their volume differences. As you might imagine, for Home Theatre PC's (HTPC) this is an important spec. What I saw in my NEC I believe were some basic Sanyo fans. If you find the noise bothersome I would seriously look into what fan you have, what the rated power requirements and CFM for it are...then find an ADDA or Papst fan that matches the airflow requirements but at a much lower volume. Then see if a certified tech would do you the favor of swappng in the quieter fans. The second major component of fan noise is the turbulence created by the protective grille or grate that the fan exhausts thru. If you're seriously into minimizing fan noise...while the tech has your case off to do the fan swap...grab your Dremel tool and open up the airflow. Search the web to see what many have done on their PC's like the forums at Sudhian dot com. Put an add on fan grille with minimal resistance if you're worried about kids or others sticking their finger into your modification.

This can all be done in a very professional manner so you're not hacking up your beautiful TV.

Sorry for rambling....

[dgsowers]

Thought I would update this thread based on today's visit from a NEC authorized service tech. The technician thought the sound was a little loud when on the wall. I could hear the fans at 20 feet. He ordered two new fans and came back today with the new parts. With the plasma off the wall and my ear right up against the old fans, the sound was similar to a playing card in the spokes of a bike. Obviously not as loud, but this is why I thought something was stuck in the fan. Off the wall, the sound did not seem as loud from a distance.

With the new fans in place there did not seem to be any change in the sound off the wall. The tech suggested sound absorbing material on the wall might help.

However, once the plasma went back up on the wall, the sound has been reduced and has changed. I have not put up any material to deaden the sound!!! This is all because of the new fans. If I listen very carefully in a quiet room, I can just barely hear the fans at 20 feet. Viewing distance of 12 feet it is not bad either. The sound has changed from the ticking sound to a more consistent "fan noise", I don't know how else to describe it. It is much less annoying. With my ear at the wall on the side of the plasma, the noise is much quieter. I can still hear the ticking noise, but it is quieter and almost seems like there are twice as many ticks per revolution, so the sound is more of a constant hum, than a distinct tick. Maybe the fan is running faster. I don't hear the sound of air movement though. Very nice surprise after being initially discouraged. The new fans appeared to be the same brand as the originals. When spun with your finger, they both sounded identical as well.

The original fan noise never bothered my wife, so this could explain the experiences of other owners not hearing or being bothered by the fans. However, I have noticed a big improvement and am very glad I had the fans replaced.

Don

[dgsowers]

Picture of inside of NEC 50XR4 when service tech was replacing the fans.