Welcome to the MacNN Forums.

Mac_X · Dec 25, 2006, 06:16 AM

My eMac's screen is starting to vibrate at the sides, and it varries from being very noticable to slightly noticable. I am pretty sure the problem is directly related to the screen, and not the computer going bad. - also, some corners darken in color sometimes, indicating its a screen fault.

I cannot prove it, since I dont get the same results every time, but I feel like it is in some way related to how many things are connected. I was thinking it had to do with the electric current, but both of the things i have connected dont draw power from the computer, they are connected to electricity plugs (set of speakers and external hard disk).

So I ask; is this due totally to the fact that the screen is dying, or do the things connected play any role?

WOPR · Dec 25, 2006, 09:44 AM

Move the speakers well away from the eMac and see if that makes a difference.

Kar98 · Dec 25, 2006, 12:22 PM

Is there a cellphone nearby?

Mac_X · Dec 25, 2006, 01:16 PM

yeah, I have a cell phone on the same desk. But I dont think it has been on that much lately.
- I tried moving the speakers, as far away as i could....... no difference.
Im assuming its the screen thats dying... since thats what happened to my family's eMac little over half a year ago. But there wwere no vibrations before that, it just didnt turn on the screen all of a sudden.

In any case, thanks

Kar98 · Dec 25, 2006, 02:28 PM

Move the cellphone at least 8 feet away from the computer.

Will C · Dec 25, 2006, 04:20 PM

My eMac screen is going bad as well, I am getting purity errors (colours coming out wrong in certain areas) which is due to the colour mask becoming magnetised. I suspect in my case the deguass coil which should demagnetise it when I wake up/start up the computer has stopped working - usually a problem with the thermistor.

A good old TV repair man (or woman - there should be more female techies!) should be able to diagnose this and hopefully fix it assuming it is out of warranty.

ghporter · Dec 25, 2006, 07:24 PM

I don't think ANY CRT-style eMacs are still in warranty. And working on any CRT is NOT for the casual hobbyist. There are a number of rather complex issues all going on at the same time that can affect the way the picture on a CRT looks. The wavy lines along the sides of the image indicate inconsistent sweep by the electron beam, and discoloration and/or darkening indicate inconsistent beam intensity. Neither of these has anything to do with the "computer" part of the system.

Now, the bad news. While these problems are workable, they aren't easy to fix. The timing system for the CRT's electron beam is rather involved - and analog - so it could be a matter of simply aging components. Beam intensity is related to how much power goes to the electron gun, and that's a whole different system. Having both problems together is Bad™. It does indicate that the CRT is itself likely to be the actual problem component.

Will C is correct in indicating that having the color mask magnetized is bad for the image, and that a normal TV repair shop should be able to fix this-it's a procedure called "degaussing" and shouldn't take much time at all. BUT...this will NOT address sweep problems that produce wavy image sides...

So solution number 1 is to get an inexpensive LCD display to use along side the rather aged eMac so the computer part is still usable. Solution number 2 comes as soon as you've saved up enough to replace the eMac with a more modern machine that does not depend on a large, hot, power-hungry, and potentially dangerous CRT. Spend $150 or so on a decent LCD (and you'll never go back to a CRT for anything-I can't wait until I can afford an LCD or Plasma TV) and you can get plenty more use out of the eMac while it eventually wears out.