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General Category => Technical support - Hardware related => Topic started by: elanstra on 14:07, 07 October 18

Title: [SOLVED] CTM 644 (apparently) missing blue colour
Post by: elanstra on 14:07, 07 October 18
I usually plug my 6128 to a flat monitor through a GBS 8200 v4.0, because I lack space for the bulky CTM. But this week I got a new table and I decided to put the CTM 644. When I connected it I saw that the colours were wrong. I used one of the BASIC codes in the 6128's manual to test the colours (images attached).


It seems clear that the blue colour is missing; the white horizontal bar is yellow (mix of red+green) instead of white (mix of red+green+blue). The pink bar (mix of red+blue) appears only red. But I'm a bit puzzled about the last 2 bars. Red and Blue appear black  ::)


Does anybody know if this is an easy repair? And what should I do? I have some basic knowledge of electronics, but I have never repaired a CRT.



Thanks a lot in advance. I really hope I can save it. It's been with me since the 80s  ???




CTM 644:
(https://preview.ibb.co/j3TkR9/CTM644.jpg)


WinAPE:
(https://image.ibb.co/bGoVtp/WinAPE.png)
Title: Re: CTM 644 (apparently) missing blue colour
Post by: Bryce on 14:14, 07 October 18
90% it's a bad connection between the CPC and the monitor. Clean the pins in the DIN socket and connector. If this doesn't solve the issue, try bending/moving the spiral cable to see if there is a broken wire inside.

Bryce.
Title: Re: CTM 644 (apparently) missing blue colour
Post by: elanstra on 15:32, 07 October 18
Bryce you were absolutely right!


It was the DIN connector on the Amstrad. I cleaned it and now works perfect again. Thanks a lot!
Title: Re: [SOLVED] CTM 644 (apparently) missing blue colour
Post by: Bryce on 15:58, 07 October 18
Easy fix. Happy Sunday afternoon gaming.

Bryce.
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