

I've disconnected all the peripherals I can to rule them out. I swapped the original Kickstart ROMs back in and they too are giving the same problem. However the power LED did light up dim for half a second then go to full brightness, as normally happens on an Amiga.

When powering on it's an immediate white screen - no black or dark grey for half a second, it's immediately white.

I swapped out the Kickstart ROMs (while using an anti-static wrist strap, of course) taking note of the correct orientation and which ROM part number goes in which socket. I decided to give it an OS upgrade so I purchased Kickstart 3.1 ROMs and Workbench 3.1 disks. My towerised Amiga 1200 came out of storage recently and I've been messing around with it a bit.
