Falcon CA401332-003 Rev D/C Service blog

[DoG]

Pin 19 seems that it has to be grounded on the falcon side to get it to work.

http://gossuin.be/images/schemasatari/A ... DAPTER.pdf

[Steve]

Pin 19 seems that it has to be grounded on the falcon side to get it to work.

http://gossuin.be/images/schemasatari/A ... DAPTER.pdf

Oh yes of course! I forgot, it's also in the instructions I've got. I'll make a toggle switch for RGB/VGA which puts the corresponding pin to GND. Thanks @DoG

[Steve]

Hey @DoG I wired up the VGA/RGB switch but still no output. I am just asking the owner what the history of the monitor port is and why it was removed. I have a feeling that its output wasn't functioning initially since I'm quite sure I've wired this up correctly.

I noticed that the video DAC has been replaced before, the soldering looks DIY and there are traces of flux I can see.

Do you think I should put my oscilloscope on to measure R G B H V? Or any other particular area.

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[Steve]

@exxos I remember recently you replaced a falcons DAC for a customer, how did you come to the conclusion that it was at fault & what can I check to confirm? (if explaining oscilloscope stuff pls do with some detail as you know I am still learning the scope)

[exxos]

https://www.exxosforum.co.uk/forum/viewt ... p=206#p206

IIRC that was not outputting signals on all RGB channels.. but it turned out it was not receiving them from the Videl .

[Steve]

https://www.exxosforum.co.uk/forum/viewt ... p=206#p206

IIRC that was not outputting signals on all RGB channels.. but it turned out it was not receiving them from the Videl .

Okay, so this is a little different since I'm not getting any sync at all. So in my case I guess I'd need to trace the h/v sync signals back? What do you think. Is sync generated by the DAC?

ps - I know the falcon is 'working under the hood' because of the normal floppy access during detection/startup and after memory test.

[DoG]

...
Okay, so this is a little different since I'm not getting any sync at all. So in my case I guess I'd need to trace the h/v sync signals back? What do you think. Is sync generated by the DAC?
...

DAC is only for the RGB bits to analog. VIDEL is making CSYNC, HSYNC and VSYNC.

[exxos]

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[Steve]

Thank you my friends, this points me in the right direction, my investigation continues

[Steve]

Okay,

I decided to go back to making a DB19 connector, based on @DoG 's idea of cutting down a DB25. I just want to make sure this Falcon looks proper and original, do I decided against a custom VGA solution.

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Seams soldered together and sanded. Looks good