dm500 help

Hi ive recently bought a dm500 (clone) after watching it on sat night it just went into some sort of boot sequence and wont stop ive managed to reset to factory defaults but now when i attach null modem cable to it , it will not find the box i wanted to flash another image to it , but nothing i do with pc and null modem cable will find it ,any help would be most welcome ,
thanks in advance
ps just to add ive tried 3 versions of dreamup now

im currently on com 1
i will leave unplugged for an hour then retry
thanks
ill report back then

ok still no joy have left unplugged for more than 1 hour
any ideas ?

i cant even get to part to flash it the image is nabilosat darkstar11 and when it ask me to plug in box when i plug it in there is green light on box . hope this helps

ive tried now 5 or 6 versions of dreamup also

only just got the box off one of the members on here
had it plugged in for less than 24 hours

yes i used it a few weeks ago on my cablebox

also used it on my tm3000

yes ive used it on my tm3000 before i got this 500

ive tried disabling all antivirus and firewalls still no joy
pulling my hair out now

ok tried that still no joy
dunno what to to now

its about an inch away from goiung in the bin now

well ive left it overnight and still same problem this morning .Ive connected it back up to tv and it lets me go into menu and everything but still cannot flash it .
Any ideas would be most welcom at this point
thanks

brummie im not sure what im doing with flash wizard
any tutorials ?