[SOLVED] High pitch noise from CRT

[sling-shot]

Recently I have been bothered extremely by a very very high pitch (near the limit of my hearing but highly disturbing) keeeeeeeeeeeeee........... kind of noise from my 17" CRT. It slightly changes in tone from time to time. Comes and goes intermittently. I am sure it is the CRT because the noise goes off the instant I switch it off. It feels like that screech you hear when metal rubs against metal but not exactly.

I have considered the possibility of it coming from the speakers but switching them off does not make any change.

Do you have any idea?

[Just17]

It is about 40 years since I worked on TVs to any extent .....  but that sounds like a line oscillator ....  dunno what it might be called these days

Found this

https://www.youtube.com/watch?v=w6j8d_C-Dd4

EDIT:
           Having watched that video I would not be inclined to agree with the idea of dumping such a CRT .....  the vibrations could probably be dampened, depending on where they are coming from.
Sometimes it is the transformer vibrating and judicious use of hot melt glue or even tie-wraps can fix it.
Not something for the user to do ...... there are very high voltages inside the TV .... not a good idea to touch any of those points 

[sling-shot]

Been thinking of replacing that CRT for some time now. Is this a good excuse? In case it is difficult to fix it.

Another thought - Will a replacement LCD panel consume less electricity than this CRT? Thinking of a 22" replacement.

[Just17]

Been thinking of replacing that CRT for some time now. Is this a good excuse? In case it is difficult to fix it.

Another thought - Will a replacement LCD panel consume less electricity than this CRT? Thinking of a 22" replacement.

Yes it is a good excuse     all excuses that work are good 

Yes LCDs consume much less energy than CRTs.

[kjpetrie]

Depends on the backlight. A CFL backlight uses around 55 watts. LED backlights more like 10 watts.

The noise from your CRT monitor could be line whistle, although I'm slightly dubious as line rates on a computer monitor should be higher than a TV unless you're using a very old 640 x 480 resolution, and well beyond the range of human hearing. The switched-mode power supply is a more likely culprit, I suspect. It could also be a corona discharge (cracked insulation allowing electrons to be sucked in from the air - at 22.5 kv it's quite difficult to contain electricity). That is usually accompanied by the smell of ozone as the ionised oxygen atoms try to share their remaining electrons more efficiently.

LCD monitors are more pleasant to use as they don't flicker at a frequency the eye can detect and their geometry is much more accurate, but they can suffer from permanently lit sub-pixels and their gamma varies with viewing angle and cannot be calibrated with tools (including display software) designed for CRTs.

[Xenaflux]

Been thinking of replacing that CRT for some time now. Is this a good excuse? In case it is difficult to fix it.

Bite the bullet and buy a 22 or 24 inch monitor.
Repairing it will cost also money and there is still a chance something else goes wrong next week.

I know that money can be tight, but think as follows, then it is cheaper.

A new one cost $200
You use the monitor for 5 years.
That brings it down to $40 a year ( lets call this 36 )
There are 12 months in a year.
That brings it down to..........s*t, the solar battery of my calculator just went flat....

Xx

[The Chief]

Recently I have been bothered extremely by a very very high pitch (near the limit of my hearing but highly disturbing) keeeeeeeeeeeeee........... kind of noise from my 17" CRT. It slightly changes in tone from time to time. Comes and goes intermittently. I am sure it is the CRT because the noise goes off the instant I switch it off. It feels like that screech you hear when metal rubs against metal but not exactly.

I have considered the possibility of it coming from the speakers but switching them off does not make any change.

Do you have any idea?

That often comes from the fly-back transformer, when one (or more) of the lamination's in the transformer core separates.  The core is several thin sheets of steel laminated together, and eventually the varnish gives up and lets them separate a few thousandths of an inch.  The only way to stop it is to replace the fly-back transformer and that will likely cost nearly as much as a new monitor.

[sling-shot]

The only way to stop it is to replace the fly-back transformer and that will likely cost nearly as much as a new monitor.

Got that. Thread SOLVED

[sling-shot]

I am eyeing these 2:

1. Samsung with TN panel type and refresh rate of 2 milliseconds:
https://www.flipkart.com/samsung-21-5-inch-led-s22b370h-monitor/p/itmd8zygmfy4gx7c?pid=MOND8ZV5ECU5TFRZ

2. Dell with IPS panel type and refresh rate of 7 milliseconds:
https://www.flipkart.com/dell-21-5-inch-led-s2240l-monitor/p/itmdf4zvqauzt2z4?pid=MONDF4ZHPUYJBYPR

What would be better?

[µT6]

lately i like more samsung than dell

better quality and image quality continues for more years, i have seen some dell that after 2 years start to show real image problems, this does happen on every brand but i have seen more on some brands