Amiga 1200 washed out video and flicker problem

TjLaZer

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Hi,


I was testing out my new ACA1221 today and got it fully licensed and wanted to see if it was going to be stable at 28Mhz. (From my trial tests it seemed to be doing fine), so I decided to copy a bunch of files to RAM: to fill it up and task the CPU and see how it would do. Came back later and machine was locked up, with LED flashing and screen looked washed out! I turned it off and then back on and now it boots up with the screen all washed out and colors look a little off, with lots of PINK, and the screen also flickers/flips every once in a while. Does it with Composite and RGB, see pics. The Car pic is RGB. Seems to work fine otherwise. So is this a big coincidence with the lockup or bad luck? Did I fry something? What can I check? :Doh:
 

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Bryce

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Have the capacitors already been replaced on the A1200? If not, maybe it's time.

Bryce.
 

TjLaZer

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Nope. Could bad caps cause this issue?
 

disco

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Are you using Indivision AGA Mk2? If so, reseat it.

Had exactly the same problem yesterday when I installed Mk2cr for the first time. Reseated it and everything is fine. Well, it was until 10 minutes later when glitches started but that was solved with a grounding wire that came with it. It's rock stable now and has proper colors.

This looks like an old monitor so you probably aren't using a scandoubler. In that case, check the wires on the cable. From the screenshots it looks like green is cut.

Nevermind, just read that it happens with both composite and RGB. The problem is definitely on the board.
 
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TjLaZer

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Actually I was able to find out that Red and Blue are not working as they should. Used ProTracker to do the Palette test and when you slide the bar the color does not change like it should. So the Red and Green lines are not feeling correctly to the DAC. Not sure if the chip is bad or some traces... Need someone to help me fix this and also do a recap.
 

Bryce

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Yes, I'd definitely recap it first and then see if the problem persists.

Bryce.
 
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