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My 21" Apple Studio Display (Blueberry - CRT) Restoration Project

Irinikus

6502
I managed to purchase a 21" Apple Studio Display (Blueberry - CRT) locally for $133.

I'm willing to go through the process of troubleshooting this unit, as these things are extremely heavy and it would be expensive as well as risky to import one due to its size and weight.

I plan on pairing it with my Max-Spec G3 B&W Tower.

The plastics are in very good condition, but because the display had been sitting in a garage for years collecting dust, it was filthy internally, as it has a huge vent on the top allowing dust to fall freely onto its internal components.

When I picked it up, I took a look through the top vent, and when I saw how much dust was inside, I decided not to attempt to power it up.

According to the seller, when it's plugged in, it receives power and when you press the power button, you hear a relay click, but there's no picture. So I asked the seller if he heard the classic static sound that these units make as they power up, when he attempted to turn it on. He replied that there was no static sound or static present when he attempter to turn it on.

The Flyback Transformers in these units are known to break down, so from his description I believe that the Flyback Transformer in this unit has more than likely failed.

The good thing is that I did a bit of research before purchasing the unit and found this site: https://crtdatabase.com/crts/apple/apple...20features which gave me the servicing manual for this unit as well as the serial number for it's Flyback Transformer. Allowing me to track down a replacement part from this site: https://technotronic-dimensions.3dcartst..._2174.html

Before commencing the troubleshooting procedure, I've decided to tare this unit down completely and give it a thorough clean.

I'll admit that I wasn't prepared for what I'd find on the inside of this unit, although I've always known that they attract dust due to the static they produce, this was crazy!

And so the disassembly of the internal components begins! (Removing the rear plastic cover was more tricky that I thought - it is a bit of a pain in the ass to remove due to all of the tabs which secure it in place.)

It’s important to photograph all of the connections before disassembling! By the way, this is the colour calibration board the Steve bragged about, and although it's the first board you see during the disassembly, it's the last board you can remove from the unit.

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Here's an exploded view of all of the sub-assemblies:

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The removal of the power module:

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The Cleaning Process:

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The cleaned Module:

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In preparing to remove the main deflection module, so I firstly removed the connections to the electron gun:

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The deflection module removal:

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The cleaned up deflection module:

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Before removing anything else, I took this series of photos to see exactly how the various wiring harnesses need to be routed:

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Finally, a look at the colour calibration board: (You have to remove all of the other modules before you can remove the module which carries this board)

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The collection of cleaned parts:

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This is as far as I can go with the dismantling for now, as I need a long T-15 screw driver, which I've ordered in, to remove the front bezel. (Which I need to remove before I can remove the intermediate bezel and the base!)

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While I wait for my long Torx 15 screw driver to arrive, I've preemptively ordered the replacement Flyback transformer for the deflection board, as I think that this is the most logical place to start in getting this thing back up and running. Considering the fact that these are prone to breaking down and symptoms described by the seller.

I have managed to remove and clean the front and intermediate bezels, as well as the base: (Hopefully I can have it fully dismantled Today!)

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OK, it’s finally completely dismantled and cleaned! (I'm still going to have to give the yoke on the tube a good careful deep clean.)

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I’m slowly starting with the reassembly:

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I'm going to reassemble it completely and will remove the deflection board later, once I'm ready to replace the flyback transformer. (The new one has arrived in the country)
 
This morning I refitted the base to the frame, as it's easier to do without the tube being installed, but still need to complete the cleaning of the yoke with canned air before I reinstall the tube.

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My new Flyback Transformer and Horizontal Output Transistor also arrived this morning!

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I'm currently waiting for a can of Canned Air as well as some Copper and Aluminium adhesive tape.

The Copper tape covers the joint between the metal plate on the base and the metal frame section, and the aluminium tape grounds the USB hub to the metal plate on the base.

One question, which of these two transistors is the HOT, as there are only these two transistors on the deflection board which match the physical size of the Fairchild HOT which I ordered?

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According to Technotronic Dimensions, the original for this monitor HOT is a BU2520DF.

And I just found it:

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Here are the specs of the transistor they sold me with the flyback:

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These are the specs of the pictured transistor:

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I've managed to clean the yoke out with compressed air and acquired copper and aluminium tape, so today I decided it was time to install the tape and reinstall the tube into the frame.

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The tube's safely reinstalled!

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This is as far as I'm going Today:

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The colour board's installed.

I couldn’t help myself, so I just reassembled the whole thing!

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I've done this just to clear my place of all the junk lying around. The Flyback still needs to be replaced, but all I need to do is remove the deflection board to carry out this component swap.

There it still waits on my desk, but at least the floor is clean of junk!

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Seeing that I have the monitor assembled, I decided to see what would happen when I tried to power it up, as I haven't done so at this point. (I wanted to confirm the symptoms that the seller described.)

At least it didn't blow up, but it shows the symptoms that the seller described.

When connected to power and the power button is pressed, the amber power LED comes on, showing that the monitor is in a standby mode.

When it's in standby mode and you power up the computer to which it's connected, you hear a relay on the deflection board click, but there is no static (The classic sound that a monitor makes as it powers up) or picture.

The fact that the relay which clicks is on the deflection board gives me hope, as this indicates that the monitor is receiving the picture information and attempting to fire up the non-working deflection module.

This surely indicates that it has a bad Flyback transformer and possibly HOT as well. (I will replace both)

I have to correct myself, IT FRICKIN WORKS!!!

I was attempting to fire it up using a PC , but I then thought, just let me try one of my G4's, and it worked!!!

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I’ve just calibrated it! (So I have a spare Flyback!)

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Now I just need to refit all of the plastics. (I'll do that tomorrow.)

Here are the current settings: (I'll move it over to the G3 B&W later, as it's for that machine after all!)

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It's now setup on the B&W!

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It’s almost time for the complete reassembly! I’m waiting for the cover to dry out completely, as I’ve just given it a thorough cleaning!

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I’ve chosen not to install this grey lining under the intermediate bezel, as the previous owner damaged it while trying to pry off the bezel. It would have looked shite!!

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The one that sits under the front bezel has been installed.

And she’s finally back in one piece!

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I currently have the monitor setup with my G3 Beige, as it's running OS9.2:

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The Apple USB Display Service Utility only runs in OS9, and I now have it installed, allowing me to make fine adjustments to the screen when I get around to giving it a full tuneup in the future:

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After running the monitor for quite a while, I have noticed that it will indeed need a Flyback transformer replacement, as every few hours I’m getting the notorious “click, pop, Zoom”, which is the symptom of a failing Flyback transformer!

Thank God I managed to get a new one!

This repair will have to wait until I have the correct tools to do the job myself.

I can live with it for now, knowing that I have the spare Flyback!

I will do an update on this in the future.
 
Nice work, and thanks for the writeup. Will be useful to others.

That monitor is way more complicated than I expected. It's a whole computer in there.
 
Thanks for photographing and documenting all of this. It is great to have resources like this in the community.

As an aside, good grief there are a ton of caps in there. I count at least 60 on the ColorSync board alone. This display would be one helluva recap job.

I've not previously seen any concrete testimony or documentation that these 21" models suffer(ed) from the same flyback issues as the 17s, so that is also useful to know. Do they use the same flyback?
 
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Thanks for photographing and documenting all of this. It is great to have resources like this in the community.

As an aside, good grief there are a ton of caps in there. I count at least 60 on the ColorSync board alone. This display would be one helluva recap job.

I've not previously seen any concrete testimony or documentation that these 21" models suffer(ed) from the same flyback issues as the 17s, so that is also useful to know. Do they use the same flyback?
I agree. I always heard, back in the day when I would send mine in to Apple to get "fixed", that it was only the smaller 17" that suffered from this.

I always wanted that huge 21, though. Nice documentation too.
 
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