Does your powersupply fan spin? Do you have another machine you can test the powersupply? (this should be eliminated as source of problems).
Green means : Error found in chip ram.
Try opening J500 to disable the 512k RAM on board. maybe it'll get you booting? else try putting another Agnus chip?
You should always clean all your amiga hardware free of dirt/dust/debrees, then the 20 year old machine works fine.
I really find that a lot of problems occur, because users let dust/dirt accumulate instead of cleaning it. Same goes for disk drives.
