I found this article on TweakHardware.com. It will walk you through adjusting the focus on that old computer monitor. It will also help you adjust the color and brightness of your monitor.
Many monitors display an unnecessarily bad picture quality. Several older monitors suffer from showing a very dark and blurry image. But it doesn't have to be this way! With a little knowledge and a couple of screwdrivers, we can make adjustments to achieve a sharper and/or brighter image.
The process is quite simple, but requires you to take the back cover off of your monitor. This is usually very simple and requires only a small screw driver. The guide on Tweak Hardware will walk you through the complete process.
WARNING
This tweak, if not done properly, can cause serious injury and possibly death to you and your monitor. Use at your own risk
My Experience
I have done this to my old Magitronic monitor and it worked great. My monitor went from a blurry piece of garbage to a monitor that looked almost brand new. The process was a bit different on my monitor, the focus and brightness potentiometers were located in different positions, but worked exactly the same. I would not recommend playing with the color potentiometers unless it's really screwed up.
After fixing my monitor, I thought I would try it on my old TV, and it worked the same way. My TV was really screwed up and the colors were way off, so I adjusted the color potentiometers and finally got it to work. It takes very long to get the color right, since there's three adjustments, red, green and blue, so expect to take some time if you plan on adjusting the color. And also try many source for testing the color. ie. DVD, Video Game, VHS, Satellite, Regular TV, etc.
To just adjust the focus and brightness it took me about 20 minutes, after I figured everything out, so why not fix your broken computer monitor or TV for free.
Link to the Article
http://web.archive.org/web/20030217070144/http://www.tweakhardware.com/guide/tweakmonitor/
by Shawn (#2160)
where can i find this information now that the site is down someone please help my tv is driving me nuts!!!!
by (#2242)
Seriously man, me too!! How can I fix this blurry monitor?
by Matt Read (#2246)
OK, try that new link. It should work.
by Busy (#2325)
Did you know this page is #1 in google for *my monitor is blurry* ? You are googly.
But yeah thanks for saving my eyes from the agony of blurred code and helping me get points toward the geek merit badge for *open electronics surgery*
by Jason (#2378)
Someone gave me a 17" monitor for free because it was out of focus. I've kept it as a spare just in case my main monitor goes out.. I used this guide to fix it in under 10 minutes, and now I have a great looking spare monitor just in case..
I also used this on a friends monitor when they complained of blurry screen syndrome.
Two thumbs up!
by Adam Wishart (#2548)
can you post the link again, I can't seem to find one that works on this page - maybe i'm being stupid?
Cheers.
by Adam Wishart (#2549)
My bad, definately being stupid, got to the article although there does seem to be problems with the site.
by Andr (#2659)
Even though I've had a long day... I know I can't think straight, but I'm trying to find that link and I can'T find it!!! It says something about robot.txt...
WHERE DO I GO, I can'T find that "new link"!!! (I need that article, cuz that monitor would be REALLY helpful)
sorry 'bout desperatefulness
??: 
Thanks
by Hakkatack (#2661)
same here i can't find the article
by Dave (#2676)
would this work on an old 1980's Sony tv? id hate to take it all apart to find out it cant be done....the thing is a huge floor model.....
by Luc Elliott (#2728)
Matt,
Would you be willing to explain how, at least in general, to fix your blurry computer monitor. Do you have to take the back cover off and if so do you make adjustments while it is on? Are there knobs under the back cover or do you have to bend stuff or clean stuff?
by Randy (#2767)
This sucks my tv has bolts on it, no screws bolts cant find a small enough one either, one bad thing after another
by GeoNOregon (#31141)
Since this is coming up so high on Google, I thought I'd add some very important information. I've been tweaking monitors for many years; I have a friend who used to have a monitor repair shop, and I learned a lot from him. I'm a complete idiot when it comes to board level electronics, so I wasn't able to pick up any repair info, but I learned how to 'tune' monitors and used to tune them for Bruce when I was hangin' out at his shop.
A CRT, (cathode ray tube), monitor is a VERY, VERY high voltage device. If the caps are not bled correctly, and you touch them with a screwdriver, you find that after you pick yourself up from the floor, (if you wake up), you'll find a ruined screwdriver on the floor somewhere. I saw Bruce pop himself a few times, and it is not pretty. One time, I was ready to thump his chest, and give him CPR cause he wasn't coming to real quick.
So, unlike many warnings you see on electronic devices, the warning on tube monitors is not overstating the danger.
With that said, there is an easy way to protect yourself, and as long as you aren't stupid and touch something with your hand, or dangle a long neck chain or necklace into the monitor's workings, you'll be OK.
If you go to a 'real' electronics store; the place where the board repair geeks go, you'll find plastic screwdrivers made for adjusting monitors. BUY SOME or don't open the damn monitor.
Alternatively, if you want to save some money, you can buy 1/8" fiberglass rod and make your own. I've had mine so long I can't remember where I bought the stuff. As I remember, I stumbled on the rod somewhere when I was shopping for something else - it might have been a plastics store, like TAP plastics. You want fiberglass rod as it is stiffer ≥
Cut yourself several different lengths. Nothing short than 12-14". (Adjusting monitors is something you want to do from a comfortable distance since you adjusting in the back and needing to see the front of the monitor. A mirror helps, if your eyes are good. (a mirror doubles the distance from your eyes to the screen.)
After you cut the lengths of rod, grab a file and turn both end of the rod into a screwdriver tip. Nothing fancy, just taper both sides. Then warp some duct tape around the middle of the rod to make a 'handle'. This is more important that you might think. Other than easier grippage, the more you increase the diameter of the rod with the tape, the more precise a tuning instrument it becomes.
It's simple physics, a larger circumference travels farther in distance than a smaller circumference. The tool will still move 90' or 180', but you have to move your fingers further to do it. This makes it much easier to make a 1/8 or 1/16 of a turn adjustment.
Something else you can do after you figure out which 'pots' do what on the boards, is drill access holes in the monitor case, (if they line up). Then you can do a quick tune without taking part the monitor!
Internal adjustment will vary from monitor brand to monitor brand, some have a lot, some have few. Generally, the more on-screen adjustment you have, the more internal adjustments you'll find. When I was learning, I'd take a look at the position of the slot for later reference, then turn it one way to see what it did to the display, then I'd turn it the other way. Infrequently, an adjustment won't do anything, if so, just put it back to it's original position.
FYI, 'pots' are little square boxes directly mounted on the boards in the monitor. They're about 3/16-1/4" square with a small slotted screw head in the middle of the square.
I always looked at the adjustments this way. The internal adjustments are 'gross' adjustments, while the on-screen, (knobs on the monitor front), are 'fine' adjustments. If the on-screen or knob has a plus and minus adjustment, you want to do internal adjustments until you 'center' the knob - in other words, you want to create the most plus or minus adjustment you can have.
I have found monitors in dumpsters, abandoned in parking garages, in a lot of places - I've brought them home, and with 15-20 minutes of tuning, I've had a great monitor. For some reason, these free monitors are always the filthiest monitors ever - I've never found a clean monitor that only needed a 'tune'.
Be safe, get or make some plastic screwdrivers, and have some fun - but I can't say it strong enough, be VERY, VERY respectful of the innards of the monitor. It CAN kill you.
GeoD