A1200 display issues with Dbl and productivity modes

[Betelgeuse]

I have a weird issue with an A1200. Whenever I try to use some productivity and all Dbl modes on a multiscan monitor I get half of the screen or less showing up. When I drag the screen down past the point where there is no image (just background colour) then the image shows up on the bottom half. It's an A1200 1D.1 revision with 2MB RAM and vanilla config Workbench 3.1 and KS 3.1, tried with an 060 board and some RAM and same issue. Monitor and dongle are fine as my other Amigas show the display properly.

[Betelgeuse]

I had a thorough look at the board and the capacitors around the RGB port have all leaked, there doesn't appear to be board damage but could the bad capacitors cause this sort of issue?

[Betelgeuse]

I don't think that's the same issue Cammy as there's no flashing or any blinking or anything, it's just half (or less) of the screen shown. I'm aware of the A1200 bug and it's just not the same thing.

[Betelgeuse]

that is not a capacitor issue or timing issue or something like that

it seems there is a problem in workbench config or monitor drivers
also something wrong on icontrol preferences

on the other way the 1.d1 are the worst motherboards ... were done in hong kong some of them comes with bad cias which produces bad cia timers and other timing issues but nothing related to caps

It's definitely a hardware issue not a software issue as a clean install of 3.1 exhibits the exact same problem.