Everyone in the comments keeps saying "if you don't know what you're doing, go find someone that does, skip the work, dont touch it", etc etc.
i'm here to say that that kind of behavior doesn't foster self improvement and learning.
here's what I suggest : learn about the job, learn about the hazards, take the precautions, get the equipment, don't let your guard down, and then do the work by-the-book.
you'll learn something in the process, both about the thing itself and the concept of maintaining a 'safety culture' around work that requires it. You won't get hurt, because you're going to follow the right safety precautions and work procedures.
Now, if you want to throw your hands up and just say "i'm not willing to put the hours in to ... " , then by all means, don't take the risk -- have it done. If you're in this for the pursuit of knowledge/skill/craft/gratifications then just pursue it as you would anything that is potentially dangerous and take the right steps.
You wouldn't tell someone to stay off a motorcycle, it's an enjoyable past-time -- you would remind them to follow safe driving procedure and to wear protective equipment.
Nice job and write-up.
As the author says CRTs are dangerous. Even when they're off they can still carry insanely high voltages. The flyback transformer is one of the more dangerous components of them.
I'm great at electronics repair and I tend to avoid them. Luckily these days that's easy :)
If you don't know what you're doing, you shouldn't attempt it. Just get a more technical friend to do it.
If you do know what you're doing you probably wouldn't need this guide in the first place :)
That 'snap' is the arc and the voltage = zero until it gets going again - repeat. This is common on old monitors as dust builds up and often a fix can be done by a careful cleaning plus application of 'corona dope' along spark paths. Turn it on in a dark room and watch/listen for the spark. Dope that path and alternate paths and dry with hair dryer. Test. There are universal repair flybacks - select what seems to fit. Usually the existing controller will serve - computer monitors are far smaller than most TV's of that era. Hardest thing is finding new old stock. To save the nation new flybacks can be wound - complex but doable. Hardest problem is adapting the space and circuit. The flyback can be wired point to point with hookup wire. Only the HV wire needs to be HV wire. Then you can zip tie the flyback in whatever space and dress the HV with respect.
> The focus knobs should be tuned so that the screen image is sharp. I don’t really have a good set of steps for this, so just play around with them until the monitor is as sharp as can be.
This explains my methodology for a lot of things in life
Thanks for sharing! I had a brand new one of these displays in 1999 when they first came out and it developed the same problem a year later. The replacement from MacMall’s warranty company (which was graphite instead of blue) also eventually developed the issue too. Good to know there’s a solution if I ever decide to fix it.
I think Apple should have recalled these.
For those interested in Electronics repairs, have a look at Mr. Carlson's Lab on Youtube: https://www.youtube.com/@MrCarlsonsLab/videos
Lots of detail and explanations. P.S. I'm not affiliated with anything, I just genuinely think this is one of the best (educational) channels out there on this.
This desoldering component technique video is well worth your time. Of all the basic electronics skills, doing this has always been challenging, particularly on older equipment where the copper traces will tend to peel up.
Having that happen is not the end of the world because a simple bodge wire is not hard to do in most cases.
But, there are times when a failure like that can really matter!
A flyback with the high voltages can be one of those times when you just want a clean replacement.
This guy shows you how to use wire to desolder many component pins at one time.
From what I understand of this, the danger comes from charge stored in large capacitors. So what is the longest that these capacitors can hold a significant charge if the crt is left disconnected from mains power? Hours/days/weeks? Is simply waiting long enough a reliable way to render a crt safe to work on?
(Irrespective of the answer to this, there is no chance at all that I would ever mess with crt circuitry. But I am curious.)
Maybe I was super lucky or somehow immune.. but as a Kid I got zapped by flyback transformers quite a bit of times.. (5 or 6 times?) It hurts,and it leaves a burn point where it touched.. but did not killed me.
Eventually I learned to ground the whole thing with a cooper cable and a resistor.
We had a bunch of these monitors back in the day, don’t remember any of them dying early. I was always afraid of taking apart CRTs thanks to those transformers in them. People used to overclock monitors back in the day to increase the refresh frequency.
I love this kind hardcore repair hacking to keep hardware going. There is no logical reason to spend time on this, yet someone did. Big respect to the author, you are inspiring!
Oh man... I used to run a network with hundreds of Macs.
I still remember that One Monitor, flyback transformer I could hear from my office cube, in another wing, one floor down.
> Opening up CRTs is dangerous. Do this at your own risk. Considering hiring a professional instead.
Hire a professional.
To fix a quarter-century-old monitor that was nothing special when it was new.
Why? I mean, I wouldn't bother fixing the thing anyway, but hiring somebody is going to cost you more than a much better brand new monitor.
I find your accent soothing.
The sad reality of externality-removed capitalism is why would you do that? In our disposable economy, a new monitor can be had for cheap. Repairing things is for the poor or nerdy. which I resemble the latter pay. Incentivizing fixing things, rather than buying a new shiny flashy thing is not a thing that we do well. Oh well. Hopefully room temperature superconductors and solar and batteries can lead is to a place of victory for the environment in place of coal.
I have a fully functional third-gen iMac (the "jelly bean") that needed its inner bezel replaced. Sourcing a non-broken bezel was one big job, but even after I did, finding someone with the knowledge and skill to repair it safely was a task. I wasn't willing to do the repair myself, it's just too dangerous for an amateur. These machines are supposed to have components that automatically discharge the screen after they're removed from wall power, but on a 20+ year old machine, no way to know whether that was working. You have to touch the screen and fasten it to the inner bezel, so repairing it without proper discharge was a non-starter.
I called around to various TV repair shops and was generally told they couldn't do it, or that it'd be prohibitively expensive. Finally, an electronics surplus store in my area referred me to a gentleman of the old-school AV hippy variety who knew how to repair all sorts of old equipment. He was able to construct a tool to ground the machine while working on it and we did the repair successfully together. It was an adventure!