Monitor making crackling sounds

[teknikal]

Hi there!

Recently, my 17-inch KDS monitor started making strange noises. Every few minutes, the monitor will flicker like it's about to turn off, but then all goes back to normal. Each time this "flickering" occurs, I hear some type of crackling sound that's a bit high-pitched.

Fearing that something bad is about to happen, I haven't been using it much. I've tried another AC outlet in the house without connecting the monitor cable to anything, and the same thing occurs.

Just today I tried it one last time and it started flickering and popping more rapidly - every 2 or 3 seconds. I understand that the monitor is probably shot, but has anyone seen this before or know what it might be? Is it worth servicing, especially if it's a minor problem? Obviously I'm not willing to spend much more than $75 to fix it.

Thanks,
tek

 

[SESaskDFC]

Howdy:

Sounds like the high-voltage circuit (the one that runs the CRT)is going.. Depending on the age of the monitor, you could probably get a new one for the cost of repairs..

Murray

 

[micker377]

As with any CRT based monitor, dust build and humidity combine to create H.V. shorts. Take it to a shop (no, you don't want to be around un-shielded H.V.), and see if it is dust or a failing H.V. transformer.

 

[Grenage]

Another possibility is that it could be a loose power cable.

 

[teknikal]

Thanks everyone for your insight. I will be taking it to a local shop when I have some free time on my hands. I'll post back and let you know...

Grenage,
Yeah, I wish that was it...

 

[1quickdraw]

It may just be dust build up. You can remove the back and try blowing the dust out (DO NOT ATTEMPT TO VACUME IT OUT) as there is Hi Voltage present even when unplugged. As long as you are reasonably careful you should be able to remove the back and blow out the dust. I recommend taking it outside to blow the dust out. Oh and Just in case you don't already know, of course you need to unplug the monitor prior to doing any work on it.

Hope this helps.


S

 

[micker377]

The "weird" picture you get when it acts up is called a "trapazoid" (spelling?). That is usually caused by a short in the "yoke". The "yoke" is the part that aims the electron beam up and down, and back and forth. Try to find a place that offers a free estimate, as this sounds like a lost cause. On modern CRT'a the yoke is aligned at the factory and epoxied into place.

 

[teknikal]

micker377,
Actually, it's more of a flicker with a solid line that flashes once or twice about 1/4 of the way down on the screen. This line is the same line that appears momentarily if I were to manually turn the monitor off while Windows was still running.

It might also make a difference to mention that when the monitor is not connected to the PC, nothing can be seen when the noises are heard.

I'm a little hesitant to take the backside off the monitor. Is it completely safe (assuming I only make contact with the plastic cover)? I know the charge will eventually wear off after a week or so, but I've never even attempted to take one apart.

 

[micker377]

Believe me, they are harder to get back together than take apart! Seriously, if you don't know what you are doing - DON'T. Besides the high voltage problem, there is a possibility of breaking off the neck of the CRT. Monitors are designed to be together. When you remove part of the case, you remove the balance and structure of the box. Consider a cardboard box, open the top and bottom and the box is hard to keep in a square shape. When open, it is very easy to tip over and break things (CRT, components, you). Besides, a horizontal collapse (picture becomes a thin up and down line) is a sign of loss of horizontal drive (component failure, not worth repair).

 

[tviman]

I had a CRT do this a few years ago - turned out that the high-voltage transformer was arcing to the case!

CRT's have become so cheap (OK, inexpensive) that it doesn't make any sense to atempt to repair them. You can buy a really nice CRT for around $80.00 plus shipping.

There's always a better way. The fun is trying to find it!

 

[08231999]

You need new mointor!!!

17" KDS with two year warrenty about $150 and up.
It will cost you more to get it fixed. Most people will
charge up about $45 to just look at it.

Hope this helps.
JCS