Please advise

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By Gloriou

Expert (114)

Gloriou's picture

14-02-2019, 18:29

Grauw wrote:

When exactly doesn’t it? When running specific software, or just randomly?

Composite video can only display colour if the colour system matches. So if the system and monitor are PAL, but the VDP is changed to NTSC by software, you will get a black & white image.

You can try the following in Basic:

VDP(10)=0

This switches to NTSC (60 Hz). Does it go black & white like you described?

VDP(10)=2

This switches to PAL (50 Hz). Does it go black & white like you described?

If this is the issue, then the solution is to either use an RGB connection, or to not use that software which changes the display frequency. Typically software wouldn’t do this, but some scene productions or cracks do I think (they may have a frequency selection if you keep a key pressed, or the Basic loader could have the above mentioned code which you can change before running it).

It happens at start up, and continues on.
I did VDP(10)=0, and color came back. But it was like forced! The screen wasnt relaxed

By Gloriou

Expert (114)

Gloriou's picture

14-02-2019, 18:35

By Grauw

Enlighted (8015)

Grauw's picture

14-02-2019, 19:15

Hmm, I see…

I’m not enough of an electronics expert to diagnose the exact problem, but maybe some electrolytic capacitors in the video circuitry dried out and need to be replaced? Or maybe they even are leaking, that happens sometimes, although I don’t think Yamaha MSX computers have many problems with that usually. You could inspect them to see if any of them either leaked (goo around the base or top) or bulged up.

Just to make sure I would also inspect the video connector, if the connections to the board are looking in good shape, although I don’t think that would cause this type of issue.

By Gloriou

Expert (114)

Gloriou's picture

14-02-2019, 20:39

Grauw wrote:

Hmm, I see…

I’m not enough of an electronics expert to diagnose the exact problem, but maybe some electrolytic capacitors in the video circuitry dried out and need to be replaced? Or maybe they even are leaking, that happens sometimes, although I don’t think Yamaha MSX computers have many problems with that usually. You could inspect them to see if any of them either leaked (goo around the base or top) or bulged up.

Just to make sure I would also inspect the video connector, if the connections to the board are looking in good shape, although I don’t think that would cause this type of issue.

I will check it and update

By Alexey

Guardian (2098)

Alexey's picture

15-02-2019, 10:38

I am not sure that using a 5 meter RCA cable is a good idea. Try with a shorter (up to 2 meter) cable.

By Gloriou

Expert (114)

Gloriou's picture

15-02-2019, 10:50

It's not that long for an RCA, it is connected to AV to HDMI module.
But forget about all that.
This case I remember it very well, that my older brother told me once that if I used Audio video it will be black and white
However I remember if I used an RF cable it will be fine

Please advise,

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