Amiga 1200 Blizzard 1230 MKIV trouble shooting help

[cabbit]

Greetings,

I am in need of some assistance in diagnosing an issue with my Amiga 1200 and Blizzard 1230 MKIV setup. I seems that the amiga will only fully boot when the ram is removed, or when i click disable cpu caches at start up.

When both are inserted i get amiga dos with a cmd prompt (Failed returncode 20) and no workbench, if i try "loadwb" it tires to load however the screen will be covered with artefacts. Booting a wb 3.0 disk will only display artefacts unless i have the ram removed or cpu caches disabled.

I have tried all my components individually on my friends amiga 1200 and they all booted up to wb 3.0 successfully without issue leading me to believe something is up with the motherboard, however my motherboard is in very neat condition so i would like to avoid replacing it.

Appreciate any ideas and suggestions on how to get this all running.

[cabbit]

I unfortunately don't have another to test with, my mates psu was non functional. However with his motherboard and my internals i was booting up into workbench without a hint of failure. My guess is perhaps this timings issue i've read about.

[cabbit]

Hi billyfish i have tried on 60/70 and maprom/no maprom each has about the same result i am afraid.