Bump. No thoughts ?
Similar to what happens to my B2000 4.4, with external 4MB card, the megachip was present or make a blank or a green screen.
Take a white eraser and clean Agnus chip and megachip contacts... (not the socket)
Check the wire and the grip...
Clean also the cards connectors with the eraser.
Remove all shavings
Never occurs since this cleanup.
Otherwise, check capacitors shape on the motherboard... perhaps it's time to change them...
