I have the same problem with a C250..I accidently pulled the cord out of the wall moving the machine....and now have a hour glass on display for 15 seconds, then goes blank...
I am trying to get a 128 MB Compact Flash, (the CF I have, the machine does not recognize it)..... to try firmware first, if that does not work, then try to flash the NVRAM...
I have written instructions for that...and the NVRAM Download..worth a try...
Email me @
jerrrbear@hotmail.com with KM C250 in subject line and can email you instructions and NVRAM firmware...