Heat is bad for CRTs, right? It shortens their life span?

[zsouthboy]

I am getting a new CRT in a week, I remember somebody posting that heat is the main enemy to vaccuum tubes..... so, would I extend the life of the monitor by adding a few fans(hell, I have about 11 on my rig already, it's not like i'll be able to hear them ), cutting out and sticking a fan in a 80mm blowhole in the top of the plastic, or something to that effect?

Yes, I know it's dangerous, blah blah blah, but my middle name is dang.... I mean... uhh.... i'll take precautions

zs

 

[rimshaker]

Heat is bad for any type of electronics in general. Built-in CRT monitor fans... i'm surprised it hasn't become standard by now. There's a huge business for cpu fans and coolers, but no one cares about their monitors

 

[Armitage]

I don't think you'll see any longevity due to adding a fan to your monitor. Might even hurt it if there is any vibration.

Just keep the vents on the top & sides of the monitor clear. I've seen to monitors toasted cuz people stacked papers & crap on top of them.

 

[Bozz]

Well I think it will help, but not the actual picture tube itself.

The picture tube's guns can only deliver so many electrons before they wear out and become coated in barium resulting in a dark picture. Most monitors today are of absolute rubbish quality and the tubes are designed to last the warranty period and then die. There are exceptions to this and buying a good monitor such as a Sony will get you something that lasts a lot longer and costs you less in the long run due to not having to repair/replace it when the "cheaper" piece of junk dies. Most cheap picture tubes have terrible guns that wear unevenly so when you get it the picture is sharp and crisp, give it 6-24 months and it will have deteriorated noticeably. This is not due to electronics wearing out but the tube itself being of such poor quality. The only way to make a CRT last longer is reduce the contrast and brightness. Tubes have a life generally described in hours, good televisions at full contrast (some call it picture) and almost full brightness should last between 5000-7000 hours while at about 30% contrast and brightness set so black just barely starts illuminating should last well over 10,000 hours. These figures represent when the tube cannot display its picture perfectly anymore, yet you still have a viewable picture. There are many of the cheapest brand monitors out there that can barely get 2000 hours out of a tube.

Basically all I'm saying here is you picture tube will die before the electronics does if you have a cheap sh!tty monitor but if you paid more for it then it would be worth considering some airflow through it to keep the electronics cool. Cooling down a picture tube will result in no improvement in it's lifespan.

Keeping electronics cool does make it last longer for two reasons - thermal stress on components and thermal stress on solder joints and the printed circuit board. Dry joints are the biggest cause of intermittent faults with electronics and keeping components cooler reduces the heat/cool cycle of components and the PCB. A dry joint forms one of two ways - the easiest to understand is the heating and cooling reason - solder is made of 60/40% lead and tin so it's a soft metal. When a metal heats up it expands, when it cools down it contracts. Many heat/expand and cool/contract cycles results in a broken solder joint and an intermittent fault usually ensues. The second reason that dry joints form is electromechanical vibration and stress. Firstly a component that's very heavy or has something leaning on it will eventually form a dry joint. The more tricky part to understand is the electromechanical vibration that occurs as varying voltages pass through the components. You can view the entire circuit board as a large electromagnet, every trace can be represented as a coil or winding - as voltage and current increases and decreases through the tracks and components it makes them move ever so slightly. This happening 50,000 times per second easily causes dry joints on circuit boards. You may have seen an old TV that makes a loud high pitched squealing noise and if you give it a good bash on the side it shuts up temporarily - that is the same thing thats happening except the component inside the TV (usually an inductor or transformer) has just repositioned itself temporarily due to your technical tap on the side

So - keeping a fan on top of a cheap monitor will not save you any money or lifespan of the monitor. Keeping one on a good monitor will.

Cheers

 

[zsouthboy]

Ok... it's not a cheap monitor....... I will keep your points in mind...

Thanks for clearing that up for me,

zs

 

[Moohooya]

Yikes, don't put a fan on your monitor!!!

I'm sure people can give you a dozen reasons to do so, or not to do so. Heat, emf, vibration and so on. But what about picture quality?

A monitor is designed to give you the best picture for the buck. All monitors. When people go down to the local monitor store, (Best Buy, Circuity City etc) they look at all the monitors and decide which looks best in the price range they can afford. All these monitors are turned on, have been running either weeks or hours if they are turned off at night, and therefor have reached their optimum operating temperature. Monitor designers design these monitors to give their best picture at these temperatures. If you add a fan and cool it down by 5-10 degrees, you'll never get the best picture from your monitor that you could.

Go down to you monitor store, and ask to see the instruction manual of a decent quality monitor. It will tell you that there is a 20-30 minute 'warm up time' until the optimal picture is obtained.

Do make sure that the vents on the monitor are not blocked. Don't put it close to a heat source. Don't artifically cool down a monitor so it can never warm up.

A decent monitor should last you 4-5years. In that amount of time, you'll be wanting it to die so you can go out and get the new 4 mega pixel flat screen for half of what you'll pay for a decent 19" monitor today.

Moohoo

 

[zsouthboy]

I hadn't thought of what happens when you do cool it...... 'k no fans for me!.....

This also explains the problems some people were having with the Samsung 700NF---- they said that when you first turned on the monitor.... the geometry would be all wrong.... but after it was on for a little while... it would be perfect....


Thanks for all your replies,

zs

Edit: BTW, to Bozz, I'm getting an expensive-ass 19" Trinitron.... so no cheap ass monitor for me

 

[Tweakmeister]

I appreciate insuring a good investment as well!

I don't run fans on my monitor. It was designed to use convection, and the monitor designers (who have 50+ years of experience) have the technicalities down of how to insure a long life (look at these old picture tubes from WWII that still work!).

While running a nice aftermarket heatsink on a chip can work wonders, be careful not to go overboard by putting a fan on anything that feels hot

 

[zsouthboy]

I guess I sorta got caught up in it, you know its like looking around for something to do becuase you're bored........

:

Ok....now that we have that straightened out...... I have my desk in front of my windows in my room, and the monitor happens to be in front of the air conditioner unit...... Is there a problem there? It won't be like directly blowing air on the CRT though, so i guess it's ok.

zs

 

[skeletal29]

yea i was gonna do that too but i was told the monitor inside is sappose to be warm so dont bother....

Well now i got rid of all that mess and i got my lappy!

 

[SKORPI0]

I've had 3 120 mm fans blowing out hot air coming from my 19" monitor for the last 2 1/2 years. They are mounted on a metal bracket (7 1/4" x 25") and are about 1" above the monitor. So far no problems, it's only turned on when the monitor is on. Got this fans from a old system w/c I salvaged. What I hate is the noise that they make!!!! :|

 

[CTho9305]

<< I've had 3 120 mm fans blowing out hot air coming from my 19" monitor for the last 2 1/2 years. They are mounted on a metal bracket (7 1/4" x 25") and are about 1" above the monitor. So far no problems, it's only turned on when the monitor is on. Got this fans from a old system w/c I salvaged. What I hate is the noise that they make!!!! :| >>



run the 120mm fans at 7 volts. mine is practically silent (quieter than hard drive) on 7V.