I'm wondering if it's possible to convert a VGA signal to use as an input to an old CRT monitor (which I believe is monochrome), and if so how I'd go about doing this? The monitor has a 6 pin DIN input (see photos below) and I'm fairly sure I need to do more than just find an appropriate adapter cable to make this work.

The monitor is a Ferguson 3MM02G5, and the eventual goal is to be able to use a Raspberry Pi to drive the video signal (HDMI -> VGA -> Monitor).

Any help much appreciated!

6 pin DIN input Input description

  • 1
    \$\begingroup\$ That's a composite video input - if you're trying to drive this from a Pi you ought to be able to do that from the composite output instead. One moment.. \$\endgroup\$ – pjc50 Nov 30 '16 at 11:43
  • \$\begingroup\$ First thing I was were two out of focus pictures, so I quit there. Closing because now I don't know what is being asked, and -1 for the sloppiness and gross disrespect of everyone here. \$\endgroup\$ – Olin Lathrop Nov 30 '16 at 11:49
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    \$\begingroup\$ Ah, it's nowhere near that bad, and certainly not "gross disrespect"; we have a model number and a pinout. Unfortunately it's old and rare enough that the model number doesn't yield a service manual, and the video format looks like a strange one. repairfaq.cis.upenn.edu/sam/vidconv.htm#nvcvgtl You might be able to just connect 4 to the pin and 3 to the shield of yellow RCA composite video and get a result. But you might not. \$\endgroup\$ – pjc50 Nov 30 '16 at 11:54
  • \$\begingroup\$ @pjc50 Could it be several things in the same connector? Perhaps the composite signal on pin 4 and ground is all this guy needs, possibly followed by a composite -> VGA converter or a forgiving monitor. \$\endgroup\$ – winny Nov 30 '16 at 12:02
  • \$\begingroup\$ Thanks guys. Sorry if the question wasn't too detailed, I'm a software guy so this is all new ground for me! \$\endgroup\$ – kingraam Nov 30 '16 at 12:09

From the nomenclature describing its inputs, and the ancient jack, and having a CRT display, am guessing that this accepts video from long ago. Long ago, video with NTSC timing format was very common. That's a wild guess, because the jack is non-standard, so it could be accepting non-standard video.
You can try to see if your monitor is close to NTSC this way: wave an oscilloscope probe around near the monitor. It will pick up the huge flyback pulse from the high-voltage circuit. If it has a period of about 64 microseconds (frequency 15.7 Khz) then it likely accepts NTSC timing.
Note that NTSC is far different from VGA timing, and your monitor will choke if you try to apply VGA - quite possibly fail permanently.
But the good news is that Raspberry PI generates NTSC video that has a very good chance of being acceptable, providing it passes the timing test (above). You might try applying the yellow RCA video (RPI A) between pin 4 and earth. If this works, and you get grungy video, experiment with tying pin 5 to earth too. If your RPI has HDMI output ( RPI B, B+, etc) then composite video out is on the 3.5mm barrel connector.
The term "75 ohm link" on pin 5 is perhaps an option to properly terminate the 75 ohm coax that is used for video connections, or it could also be a properly terminated video input. So you might try applying RPI video between pin 5 and earth.
These are all guesses. Your RPI might be at risk - at least the old video generator is at risk (I doubt that HDMI is at risk).

  • \$\begingroup\$ Thanks for the detailed response! One thing, it's a UK built monitor, does this mean it's more likely to be PAL rather than NTSC? \$\endgroup\$ – kingraam Dec 1 '16 at 10:39
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    \$\begingroup\$ @kingraam From what I see, RPI is configurable to put out PAL video or NTSC video. If your monitor accepts 115v AC power, it is likely NTSC. If it accepts 230v AC power, it is likely PAL. Read RPI documentation to find out how to reconfigure. It is a chicken&egg problem - you likely need working video to proceed with re-configuration - it is very hard to do it blind. I would give it a try. I'd hope that RPI has a way to fully reset. \$\endgroup\$ – glen_geek Dec 1 '16 at 17:51

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