Color Monitor don't show every color

[harzretro]

Hello,

i am testing a color monitor with two cpc's and have a strange problem. 
Not every color is shown. Border 26 make a white border. Border 25 and 24 make the same yellow. The Computer is starting with a black instead a blue screen.

I'm no technican, but what could it be?

Best regards 
Axel

[eto]

Please type in 

INK 0,2

will you see some blue then?

[harzretro]

Please type in

INK 0,2

will you see some blue then?

Yes, i see the same blue as with ink 0,5

There is no colochange when i do color 0,2,5

[eto]

Same issue on both CPCs? 

If yes is the picture of the monitor maybe just too dark? 

[harzretro]

I made two pictures which show the problem ...

[McArti0]

GA 40010 not make 50% blue?

Border 13... and tell what's color.

What monitor are you using?

In the original one, maybe the 100 ohm resistor to ground doesn't work.

[eto]

Weird, dark red and dark blue are completely missing.


And you say that it's happening with 2 different CPCs?

[harzretro]

border 13 makes some kind of green
Second picture pen 13.

It is the ctm 640.

[harzretro]

Weird, dark red and dark blue are completely missing.


And you say that it's happening with 2 different CPCs?

I test it with a 464 and 6128.

And i can test it with some more cpc's ...

[eto]

border 13 makes some kind of green

can you try border 13 and ink 0,9

is that the same colour for border and background?

[harzretro]

border 13 makes some kind of green

can you try border 13 and ink 0,9

is that the same colour for border and background?

Not really, but yes ....

This nakes a nice green screen with 3d efect ...

[eto]

Weird, dark red and dark blue are completely missing.


And you say that it's happening with 2 different CPCs?

I test it with a 464 and 6128.

And i can test it with some more cpc's ...

If it's the same effect with all CPCs it's unlikely to be something in the CPCs. I can't imagine they fail all identically.

It's a bit a surprise that white is white if the dark red and dark blue are missing. Not sure what can cause this but maybe Bryce has an idea. 

Btw:
Did you clean the monitor connector? If you have a glass fiber pen that can help to clean the pins properly and make sure it has good connection. 

[harzretro]

It looks like it is inside the monitor!

I cleaned the contacts without result, but then i wanted to make something and randomly i hit the monitor - and - the background was blue! 
Just less a second, but i can repeat it!

[ZorrO]

I would add some blue and red knobs at the end of the picture tube.

[darkhalf]

i hit the monitor - and - the background was blue! 

I'm thinking that the inside the monitor the board which connects to the back of the tube is not connecting properly to the pins. Or something along those lines. The board has knobs and driver transistors for each colour