Monitor fix - better cooling.

[bobatkins]

I recently posted a question about replacing a dying monitor - and

thanks for all the suggestions!

 

I did, however, manage a temporary fix for my trusty old GT775. It

was showing uneven screen colors and some lines, even after degausing.

 

What I did was cut a 4" diameter hole in the top of the plastic case

and bolt on a 120mm cooling fan. That seems to have cured the problem

for a while. It has been pretty warm here (temperatures in the 80s

and 90s and my office isn't very well air conditioned) so I suspected

maybe temperature had something to do with the problem. Seems I was

right.

 

The only downside is that I saw slight display jitter with 75Hz or

72Hz refresh rates (1280x1024) which I suspect may be due to the

stray magnetic field from the motor (even though the insides of the

monitor are screened inside the plastic case with a metal shield).

However at 60Hz it's rock stable.

 

I'm still probably going to seek out a replacement, but the urgency

is somewhat less now!

 

I wonder why monitors never have active cooling? All the ones I've

seen are just convection cooled. The air coming out of the fan on the

GT775 is noticably warm, so obviously it's doing some good.

[john_gill]

After 2 faulty monitors I too added a cooling fan to the top of the third one and (so far!) its worked perfectly. I bought one for a few pounds from a computer fair that is connects to a spare connector on the PC power supply so it powers up when the PC is turned on.

 

I've not seen any flickering with mine at 1280x1024 @ 75mhz.

 

The fan just clips onto the vent holes in the monitor casing - no cutting required.

[frdchang]

i think they spec out the components so that they can do without the fan and have the monitor last about 4 years. (which is pretty darn good)

[coconutdaydream]

i would've first discharged it, then cut out two holes. one on one side and another on another side. if there are heat sinks, i would have a fan on one side of them pulling air away from then, and the second fan pushing air from the outside onto them. or add heat sink somewhere, then do the fan placement. just a suggestion.

[kelly_flanigan1]

Fans add to the cost; are noisy sometimes; and have their own short lives if a cheapie with only a sleeve bearing and goober grade grease. In some industrial applications a high grade fan is added with a filter; to pressurize; ie move clean air into the monitor; and exhasust the hot air.

[bobatkins]

I suppose cost and noise might be the issue, but you can get a pretty decent, quiet fan for under $10, probably under $5. I've seen some selling for $1.50 retail (though I'm sure they are not the highest quality!). PCs are crammed full of fans. Mine has 3. They are all pretty quiet and (I'd hope) designed for a significant lifetime. PC fans are a pretty mature technology.

 

Those with a cynical and suspicious mind might think that if monitors run hotter and fail earlier, it could result in increased sales of new monitors. But of course that couldn't possibly have anything to do with it, could it...

 

Since monitors are "designed" to be convection cooled and have slots in the base to draw in room air and at top to exhaust hot air, Just putting a fan on top which pulls air through the system is probably the best design. There really are no heat sinks in there, just lots of heat generating components crammed under a huge CRT!

[carl photography]

Many years ago, I bought an IBM color monitor (640x480) that had a built-in fan. It cost

$4,000 new....

 

Brandon 's Dad

[ilkka_nissila]

It doesn't take a cynical mind to think that products are designed to fail eventually. My grandparents had a refrigerator which worked for 30 years without problems, while nowadays they fail quite quickly (5-10 years). You'd think that it goes the other way but no.

 

I'm on my 5th Epson photo inkjet. And I only print about 100 A4s a year. Actually it seems that the inkjets are improving in durability, both in terms of print archivality and the machine itself has fewer problems.

 

Fortunately you can always add a fan to your next CRT (if you get one).

[byronlawrence]

If you spend a LOT of money on some products they will be made to last, like kitchen aid mixers (get one now before they sell out) nice dishwashers with stainless steel everything, Furniture made of real wood and quality construction. Leather furniture with high grade thick leather, expensive cars, Usually european now etc. you get the point.

 

Electronics tend not to be no matter what though. especially now .. I have a Marantz Audio receiver that my uncle gave me years ago and he had it for years, it is a beautiful peice and it still works great,,, the Pioneer AV receiver died after 3 Years (trumpets in background with a 3 gun salute).

 

I like that add a fan to the monitor idea though, if it will add more time to the life of the monitor I have now i will willingly sacrifice a little noise.

[oskar_ojala]

Have you checked for dust? It accumulates, then messes up cooling and so forth. Some models last longer, it's just that one can't know for sure when buying!

[WJT]

Actually Bob you should see several small heat sinks on the board. Most notably would be one that the horizontal output transistor is mounted to. This is generally located near the high voltage flyback transformer, which is being driven by that transistor. The vertical output stage would be similarly cooled. <p>

I have never seen cooling fans in any monitor. Even at the office (Television Studio) where we have some very high-end equipment, they have always been cooled by convection. An $8000 Sony monitor and a similarly priced Barco have been running 24/7 for the last five years without any cooling. But that is not to say that it is a bad idea.<p>

One possible concern would be that the increased air flow from forced cooling would bring into the cabinet a greater amount of dust. The high potentials within the cabinet would entrain all that stuff and might actually make some components run hotter. Just a guess. I would put filters on the fans.

[kelly_flanigan1]

In some casinos the monitor is custom mounted in a "keep track of player quality" desk; were comps and data entry are done. The monitors sometimes have extra fans; also the computers do too.

[WJT]

One last thought. It would be better to mount any fans in a seperate cabinent (with filters) and duct the cooling air into the monitor, say, from a distance of 4 or 5 feet. The metal screen that Bob mentioned above is for RF shielding and not for stray magnetic fields. <p>

The professional grade equipment that I referred to have really massive heat sinks in place of fans. The rotating magnetic fields that some fans generate could degrade the geometry of the set.<p>

In a casino this would not be that much of a problem. But if you need to know <i>exactly</i> how a camera is performing, or how a digital image will look, it becomes a concern.