Cap Kit for D32/D64

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unumlapis
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Re: Cap Kit for D32/D64

Post by unumlapis »

Right, got the needed transformer to build a new power supply for the Dragons and with the new PS I get the following values:
d32-d64_power_board_measurements.PNG
d32-d64_power_board_measurements.PNG (11.79 KiB) Viewed 7747 times
So above looks really good. But, the d64 did have one capacitor which has leaked so going to replace the caps on both power supply boards for both d32 and d64 including the regulators. After that I'll move on to next step to connect the power boards to the motherboards.
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unumlapis
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Joined: Sat May 04, 2019 11:29 pm
Location: Malmo, Sweden

Re: Cap Kit for D32/D64

Post by unumlapis »

Well, got around to quickly put together the replacement PSU for the dragons and testing two cases; grey one kind of look a bit more retro where the black one has way more place and looks a bit modern and as well is ventilated.
dragon_psu_replacement.png
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robcfg
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Re: Cap Kit for D32/D64

Post by robcfg »

Great stuff!

I like the black one a bit more, but both like really good.
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unumlapis
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Location: Malmo, Sweden

Re: Cap Kit for D32/D64

Post by unumlapis »

Agree the black one looks best and its a bit more spacious inside so it's easier to fit switch including fuse holder instead of internal fuse holder. But, the black case is way bigger (150x110x94mm) than the grey case (115x90x55mm). Think I'm going with the black case :D
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unumlapis
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Location: Malmo, Sweden

Re: Cap Kit for D32/D64

Post by unumlapis »

So, I finally received the cap-kit including the new voltage regulators for both th Dragon 32 and 64 from RetroTech so this Friday evening I just had to get started to replace the caps and the voltage regulators. So far I've done reg and cap replacement on the Dragon PSU-boards and holding back on the motherboards. But, the LM7805 I believe wasn't in the best shape; well at least when looking at them and by the end of the day I did get better output value from both PSU-boards for the D32/64.

Here is the snapshot of the LM7805 which I replaced on both boards:
Dragon32_LM7805.jpg
Dragon32_LM7805.jpg (324.1 KiB) Viewed 7506 times
And the final Dragon 32 work done and quickly putting together the Dragon test test whether it worked or not:
Dragon32_Cap-Kit_Replacement.jpg
Dragon32_Cap-Kit_Replacement.jpg (1.36 MiB) Viewed 7506 times
And Yes, it works not perfect, so next step was to quickly test the Dragon with the new Beetronics 17" 4:3 screen which I recently bought. Worked fine but need to tweak the image a bit to get something that looks nice. But, that's for another evening :)
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unumlapis
Posts: 103
Joined: Sat May 04, 2019 11:29 pm
Location: Malmo, Sweden

Re: Cap Kit for D32/D64

Post by unumlapis »

There there, got the Dragon 64 PSU-board fixed now also with cap-kit including new voltage regulators which also improved the output voltage from the PSU-board. Here is what the voltage values from the PSU-boards looks like now:
d32-d64_power_board_measurements.png
d32-d64_power_board_measurements.png (11.52 KiB) Viewed 7484 times
So currently the same upgrade done as the Dragon 32 on this Dragon 64:
Dragon64_Cap-Kit_Replacement.jpg
Dragon64_Cap-Kit_Replacement.jpg (1.28 MiB) Viewed 7486 times
What I did notice was that the Dragon 64 did have a bit more vertical banding lines in it's screen image compared to the Dragon 32. But, I just need to compare how much of this artifacts actually comes through when using a CRT-monitor. Assume that the Beetronics does do a certain level of enhancement of this banding issue. It's the same issue that can be seen on the Commodore 64 where there are exists kits such as the LumaFix (GitHub resource as well available) - does similar solution been looked into for the Dragon/Tandy CoCo?
Beetronics_D64_PictureModes.jpg
Beetronics_D64_PictureModes.jpg (1.15 MiB) Viewed 7486 times
The above photos are underexposed and much darker than in reality; but I'll take some new shoots to show case how the image really looks like. Currently I'm focusing on the computers.
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