A friend of mine has a 440CDT that's not powering on. I have one of these as well and told him to take both cmos and backup batteries out before he tried it and he did, they were a bit corroded but not any more than mine and he cleaned the corrosion out of the connectors. His gives one blink and then three short blinks of the caps lock key and shows no display. The one and power in leds are both on and green when he turns it on. It did have a ram expansion but taking it out made no difference.