Replacing the bad flyback transformer in Apple's Studio Display 17"
riveducha.com
riveducha.com
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!
Excellent anecdote and love to hear that these people still exist
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.
The trick is, that professionals often need to know how to do something just barely safely so that they can do it fast and efficiently.
But a hobbyist doesn't need to do it fast, so you can do it very safely.
In this example, learn how to ground out the equipment, do so, and then leave it for weeks, etc.
Take your time, get educated, when possible talk to people and get the task done.
Over time a lot of best safety practices overlap and blend together and one learns how to be safe without so much angst and unknown prep.
Doing things yourself adds right up too. After a few years you will end up quite skilled and the payoffs start to have real impact!
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 technique helps a lot with traces being damaged.
There's just a lot to consider, and extremely high voltage stuff isn't really my area. I tend to do more low voltage stuff. When things go wrong with high voltage they tend to go wrong pretty spectacularly, and can cause serious bodily harm too. I just prefer not to take the risk. I'm similarly cautious with Li-ion and Li-Po battery charging circuitry. I don't like to mess around with those and if I repair them it's purely a like-for-like repair.
Another thing is that when I started with electronics CRTs were still very common and I wasn't skilled then, as such I had a lot of respect for them and a lot of caution. As my skills grew, CRTs became obsolete so I never really got comfortable with them and the apprehensive feeling remained.
But I think I have skills with electronics yes, I repair a lot of electronics, designed some of my own and I also built and modded some radios, and came up with some of my own mods (I have a ham license too).
I'd still replace the worst split rims with at least deuce rims.
I never got zapped which is a good thing since yes, that can be unpleasant and - depending on when and where it happens - dangerous. Discharge those tubes and cascades before you fiddle with them, use a screwdriver connected to a ground wire which is connected to the metal tube frame. If you want to do it 'professionally' you'll want to put a HT resistor in that wire, otherwise just zap the thing by sticking the screwdriver under the plastic cap on the high tension connector at the tube.
I.e., you select the discharge mode, put the probes on a capacitor, and watch the voltage go down, while an internal current limiter makes sure that it happens at a safe rate.
The better option is the Fluke 80K 40.
https://www.fluke.com/en-us/product/accessories/probes/fluke...
Here's a recent Twitter video showing what happens when you combine a flyback transformer and faulty insulation: https://twitter.com/zh1nu/status/1673487720780529664
But my use of the word "maybe" is more because of overall confusion about the word "big".
But this only works up to the voltage the multimeter is rated for (i.e. usually 300 or 600 V). If you wanted to make it safe to put 30 kV across the multimeter, it'd have to be designed with sufficient insulation etc. for that.
The flyback transformer can fucking kill you, and anyone who needs this webpage or is interested in the instructions (ie someone not working professionally in electronics repair and aware of such hazards) is less likely to know that.
We do have the mantra in the styropyro discord "Do not the MOT" (Microwave Oven Transformer) but we all know it's harmless without power on it.
This explains my methodology for a lot of things in life
I think Apple should have recalled these.
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.
(Irrespective of the answer to this, there is no chance at all that I would ever mess with crt circuitry. But I am curious.)
I recall repurposing the Gauss gun as a tiny "handheld" EMP that would vaporize a section of wire. Made a Win95 thinkpad (ancient now, old then) do funny things.
When working with high voltage/power equipment, its best practice to keep the capacitors shorted while you are working to keep dielectric absorption from “recharging” the capacitor to 1-15% of its rated voltage.
[1]: https://academic-accelerator.com/encyclopedia/dielectric-abs...
When working with high voltage/power equipment, its best practice to keep the capacitors shorted while you are working to keep dielectric absorption from “recharging” the capacitor to 1-15% of its rated voltage.
Eventually I learned to ground the whole thing with a cooper cable and a resistor.
I still remember that One Monitor, flyback transformer I could hear from my office cube, in another wing, one floor down.
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.
> 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.
There are folks out there who spend their time fixing unexceptional cars such as old Ford Orions, Austin Metros, VW Golf Mk 3's (poverty spec) and so on. In their day these were the most boring of the mundane mass market motors you could buy.
But it's about capturing and snapshotting a point in time. Sure this particular monitor was probably crap, but combined with a same period Mac it's a time capsule.
You might think it's a waste of time, for others it's a hobby/past time. And it's one less thing in the landfill.
The replacement parts have a footprint, and a newer monitor might use so much less power in operation that it’s more efficient to make and use it than to continue to use the older CRT.
I really wish there were an easy way to work out if this was where the ‘efficiency crossover happens in X years of use’ point was. For example, I have a perfectly usable Thunderbolt 1 [edit: Thunderbolt 1 dock] that meets my needs. But it uses 5-10W of power more than a new Thunderbolt 3 or 4 one would. Should I continue to use it or switch to a newer one?
If your usage isn't continuous (which it probably isn't), that'll reduce your electricity cost and extend your break-even point even further; if electricity costs more in your region, it'll shorten it (average EU energy prices are around double that of the US IIRC, and some countries are much higher). But it's still going to take a while to break even if the efficiency improvements you're considering are in the 5-10W ballpark; that's not all that much power in the grand scheme of things.
Whether it's better to buy a new monitor or run a rescued CRT isn't merely a financial calculation based on manufacturing and operating costs and emissions. For retro gamers and CRT fans, LCDs are usually not a replacement for CRTs in gaming and media consumption, unless you use emulators and CRT shaders, or expensive scaler boxes which apply simulated CRT effects to real consoles' video outputs. And for all but the most obsessed CRT fans, CRTs are not a replacement for modern high-resolution LCD monitors for web browsing and office tasks (the sharpness, lack of flicker, and not having to juggle VGA DACs is a major advantage).
In practice the ideal display is a complex calculation based on scan rate (SDTVs can't show high-resolution signals and VGA monitors usually can't show television signals), display size (>40" LCDs are easier to get and move around than >30" CRTs), cost and reliability. Some people have multiple CRTs they maintain and use for different purposes (alongside LCDs), but I only have the space and energy for one VGA monitor (though I envy those with entire game rooms filled with vintage particle accelerator displays).
Many people don't have reason to prefer a CRT, and that's fine too. Lots of non-CRT options out there to use.