Fans
 

Has anybody ever thought of installing fans on the rear of a flat screen? Something just to get the air moving. Might prolong the life of the caps, etc.

I think manufacturers stopped installing fans when they switched to LED zone backlighting.

I still have a 2005 Sharp with a fan that can be heard when it’s running. Two other flatscreens, one a 2011 70 inch have LED backlighting. Very little heat and mounted on a wall. My OLED has virtually no heat that can be felt by touch.

Samsung had some that would clog with dust and give a warning on the screen and then shut the set down. Also replaced a few noisy ones that were really loud especially if the set was mounted on a wall.

Early plasmas all had them. As they switched from mosfets to IGBTs they ran cooler and the fans went away. I used to add them to most LG plasmas as they ran scalding hot even when they were running properly. As plasma displays got older, the plasma panel started drawing more current and the sustain boards ran hotter.

Most modern TVs suffer LED failures these days. When LCD TVs first came out, they used CCFL tube back lighting. Typical hours is 80K or more. We changed a few tubes here and there and some inverter transformers.

When LED TVs were introduced, we assumed back light repairs would go away, but we soon found out that LED back lighting can fail in as little as 1000 hours.

Forget the fan. If you want to extend the life of a modern LED TV, go into the menu, find the back light adjustment and set it to half of what it is now. You will get 5X the life out of the back lights that way.

John

My old Panasonic Plasma from 2009 has five fans, I didn't know it had any because they are ultra quiet.
The newer one from 2014 doesn't have any that I can see or hear and it gets quite warm, you can feel the heat radiating from it when you are standing close to the screen.

I thought about getting a fan that would plug into the USB port and taping it to a vent, but that would tend to load the set up with dust so I just left it alone. Waiting for it to die so I can get an OLED, but I could be waiting a while.

Fans do no harm, and most likely do good in most cases.

But I wouldn't get an OLED unless you are buying it for a theater room that will see relatively little run time. OLEDs replicate plasma pictures for the most part but have a shorter life than any display
.
John

That's my biggest fear, I know they were having a hard time getting OLED to last, then all of a sudden it's not an issue? This is one reason I got a new Plasma when they discontinued them in 2014, even though the old one worked fine, I didn't want an LCD.
Also the choices seem to be LG or Samsung, neither brand inspires me with confidence.

Today, all manufactures that sell OLED televisions use LG panels. In 2013, LG adopted WOLED. In this panel, the light source is white OLED material. This light is passed through WRGB color filters. This was their way of getting around the lower life of blue OLED material. Samsung got into the OLED business briefly, but quickly abandoned OLED due to low panel yields. Samsung does not currently market OLED televisions. A 2016 Korean study showed that LG’s white OLED has a life span of 100 thousand hours. That is the equivalent of running the set 10 hours every day for 30 years. OLED televisions have eclipsed plasma displays in terms of contrast ratio, infinite and unmeasurable, no loss of contrast or color quality 85 degrees off axis and a wide color gamut DCI P3.

The bad press about OLED came from studies made in 2008 measuring the life spans of RGB OLED material prior to LG’s invention of WOLED. Since LG only uses white OLED as the light source and filters for WRGB, they circumvented the life span problem of blue which had the lowest life span as well as red and green.

We see more warranty failures of OLED displays than any other previous technology by a wide margin.

As for the 100K lifetime, we'll see. We were told at the service seminars that LEDs would last well beyond CCFL, but field examples told a different story.

Any filtering scheme is still subject to fade, particularly the blue because it's nearly impossible to to filter out UV light from the source, even LED lighting. Plasma, LCD TVs, LCD projectors (particularly) show evidence of yellowing as they age. The only displays that haven't shown this in my experience is the old Pioneer Kuro plasmas and any micromirror PTV with a glass color wheel.

John

My old Sony 40" CCFL, I just checked, 65,535 hours since 2008 when I bought it. Has never been serviced. Only issue is the blue that I may eventually have to replace it for. It is apparently fading and I think you just confirmed what I've been seeing. I have to run the red and green all the way down to get close to a gray scale now.

I'm not completely sure but I believe at least part of the yellowing in CCFL TVs might be a color temperature shift of the tubes themselves. It certainly isn't all of it because occasionally I'll still change a single open CCFL tube from scrap stock, and there's not a lot of difference of gray scale when viewing a white pattern in the area where the replaced CCFL tube lives. But we certainly see the yellow mange in high-hour LED back lit TVs as well.

John

The 50" Runco plasma monitor I had had fans in it, pretty quiet though, I didn't ever hear them run. As for OLED, I'm waiting for some kind of flexible TV that I can roll back up into the ceiling like a projection screen :D

That's an insane number of hours, you must leave it running all the time?

I had a Sony LCD rear projector for my first HD set in 2004 or 2005, it had 10,000+ hours on it when I replaced it in 2009 with a Plasma during Circuit City's closeout sale, I thought that was pretty heavy use.

The 2009 set got replaced in May of 2014 with another Panny Plasma, the old one worked but I was afraid it would die and no more Plasmas.

I just checked the hours on both Panasonics, they are within a few hundred hours of each other, the newer set has fewer hours but more on/off cycles.

I watch a lot less TV than I used to, though Isolating has kind of upped the time spent in front of the TV again.

Gets turned on about 6:45 AM and turned off around Midnight so it's on about 18 hours a day, like me!

To offset that I have my 2002 Trailblazer, I am the original owner, with 32,000 miles on it. One might think I watch a lot of TV and never go anywhere.

Well this is odd.. the Sony's hour counter has stopped counting. Still on 65535 hours like last week when I checked it. I guess it ran to the limit. I'll have to check the power on counter and see if it still counts.