12" Apple RGB Focus Issues

[Scott Baret]

After nearly a year of not being used, I got my 12" Apple RGB that I've had for 18 years out today. It has one problem--the focus seems to be quite off. Text and patterns are blurry (though readable) and it looks as though this display needs a good focus adjustment.

I've done focus adjustments on tons of 9" B&W screens, but never on a color monitor. Do I have to adjust red, green, and blue individually or is it all one control? Also, where is the control on the inside of the monitor to adjust this?

(I have a few extra displays that I may play around with first if need be--this particular 12" means a lot to me since I've had it so long).

 

[tomlee59]

{snip}
I've done focus adjustments on tons of 9" B&W screens, but never on a color monitor. Do I have to adjust red, green, and blue individually or is it all one control? Also, where is the control on the inside of the monitor to adjust this? {snip}

There's just one focus control. I don't know where it is on that model, but it shouldn't be too hard to find. Start your search in the general vicinity of the flyback transformer (in large monitors, the focus control is often integral with the flyback), and within the crt socket circuit board assembly.

If you want to take the fun out of it, you could also download the service manual.

 

[Scott Baret]

I'll play around with it sometime, probably on one of my other 12" displays first so I can make sure I know exactly what each does. When I get around to this I'll make note of what does what and make a diagram for anyone interested.

One other question, though--what would make the display come out of focus? I'm guessing just age, maybe inactivity? Aside from the focus there are no other problems--the color is good, no burn-in, hasn't been used excessively (I'm the original owner and know about how much time has been logged on this display).

(I do have another 12" that works perfectly in poor cosmetic condition that I can take parts from if need be).