i switched off my dm 500hd last night to "cool off"

i havent changed anything last week in my dm

this mornig tried to switch on but it wont boot : green light turns imidiately to red.

i tried to flash it several times using dreamup ans also http methods= no result as it wont finish the prosedure because the image is flashed but it never boots from itself (green button turns to red at once)

i tried hyperterminal (connects perfect) and tried restore to default settings= no result again.

tried flash second stage again , original image many times but the same result all the time: dm wont boot ......

any help is highly apreciated ....