I have a similar problem with my 4000D. Basically, it won't boot for anything. The only signs of life I can get from it are the floppy light flashing and a green screen (that sometimse flashes three times) if I pull the chip RAM before turning the 4000 on. I have thought that it might possibly be the PSU. But I more inclined to think that the motherboard, or something on it, has died.
If you do get your 4000 to boot. Let me know what you do so I can try it on mine.
