[Irinikus]

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.





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





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.

[robespierre]

Looking very good!
You already know that the tube neck is the most fragile part, so at risk of being otiose I would point out the correct order of reassembly is to leave the tube face down and set the bezel down over it.
You definitely don't want to risk dropping the tube on its neck.

When you inspected the tube face, were you satisfied with the antiglare film? No scratches?

[Irinikus]

Looking very good!
You already know that the tube neck is the most fragile part, so at risk of being otiose I would point out the correct order of reassembly is to leave the tube face down and set the bezel down over it.
You definitely don't want to risk dropping the tube on its neck.

That's exactly my intention, I'm going to place it face down on a table on a blanket and then place the frame over it and rotate it, so that I can access and tighten the four securing bolts from the table's edge. (The reverse of the process I followed to dismantle it.)

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When you inspected the tube face, were you satisfied with the antiglare film? No scratches?

I was!

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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?

[Irinikus]

I have contacted Technotronic Dimensions, the company that supplied me the Flyback Transformer and the HOT to see if they can help me out with this question

[robespierre]

Do you have the schematic? The collector of the HOT has continuity to the H.DY H pins on the yoke connector, through a choke.
If you can't find the schematic, refer to the GDM-FW900 schematic (the HOT is Q515 2SC5570 located in the center of the heatsink).
PM me if you can't find that one.

[Irinikus]

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

And I just found it:



In this case it's the large one on the end of the large heatsink, close to the Flyback Transformer.

[robespierre]

If the design is anything like the FW900 and other late Sony displays, there is a separate transistor for the horizontal drive (which goes to the yoke) and the HV oscillator (which goes to the flyback transformer).
In the FW900 schematic, those are Q515 (a 2SC5570) and Q901/Q906 (two 2SK2655's) respectively. The H Drive transistor is on the long heatsink along the edge of the board, while the HV FETs are near the FBT (which is opposite to the long heatsink), and have their own small heatsinks.

[Irinikus]

If the design is anything like the FW900 and other late Sony displays, there is a separate transistor for the horizontal drive (which goes to the yoke) and the HV oscillator (which goes to the flyback transformer).
In the FW900 schematic, those are Q515 (a 2SC5570) and Q901/Q906 (two 2SK2655's) respectively. The H Drive transistor is on the long heatsink along the edge of the board, while the HV FETs are near the FBT (which is opposite to the long heatsink), and have their own small heatsinks.

This board doesn't have those numbers, however I think I've pictured the two transistors. The one in the centre of the heatsink has two high power diodes mounted next to it (If that helps in any way) and it's also closer to the coupling that goes to the yoke.

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



These are the specs of the pictured transistor:

[robespierre]

I get bogged down with specs, but one thing that's important to understand is that the H drive (HOT) is always a NPN transistor, not a MOSFET.
MOSFETs' Miller capacitance makes them unsuitable for integrating ramp circuits. But they work fine for driving flyback transformers.

[Irinikus]

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.







The tube's safely reinstalled!