exxos's Atari, Amiga & retro forum

@PhilC I might de-solder the monitor socket & put it in the ultrasonic.. I did try the good old wiggle but the colours didn't seem to change. I don't have the test equipment for checking multiplexer output, besides my multimeter.

Just an update.. removed / ultrasonic'd the rgb port, re-soldered.. still yellow

I was thinking of de-soldering the r g b matrix chips and putting them back in a different order, to see if the output changes - does this sound like a good idea?

Steve wrote: 01 Jan 2021 17:25 I was thinking of de-soldering the r g b matrix chips and putting them back in a different order, to see if the output changes - does this sound like a good idea?

If your going to do that, might just be easier to get a new chips ?

Yes but it costs zero pounds and can only give me good information?

Okay - I'm in the mood to try to fix my H5 yellow display finally. I'll need some pointers if possible from you kind fellows. I now have my scope! So can test things properly. Or should I just buy 3x new matrix chips for r/g/b to start with.

I would start with holding down reset to get a white screen and make sure all the shifters RGB bits are all toggling , then try colour test on the diagnostic cart.

@exxos Okay - hopefully I've probed the right pins and gathered good data? Probed pins 6, 7, 10. R G B. Scope in auto mode.
Pin 6, red: Pin 7, green: Pin 8, blue: Videos of reset behaviour (As I'm not sure what I'm seeing, need help with understanding)
Red:
Green - same
Blue:

There is 3 bits for red green blue..

I know it's bad to spoon feed to teach people, but I might need at least one spoon full. lol :) Am I anywhere in the ball-park with how I scoped the pins, to see these bits is it a setting in the scope? I really don't know, I'm new to this I apologize.

edit:
I may have found it, so scope pins 21, 22, 23 etc?

Steve wrote: 20 Feb 2021 17:55 I may have found it, so scope pins 21, 22, 23 etc?

Yep, R0,R1,R2 etc

EDIT

Then check them on the outputs of the buffers..