dreambox 500hd original looses bootloader/firmware


Hello everyone
I have a problem that I would like your help.
I have a dreambox 500hd original v1 bootloader 84 which whenever it gets turned off loses the firmware.
I tried several times through the dreamup with correction of bad sectors but if you disconnect from the power is again without the firmware installed, in this case I use the newenigma, I tried others but it always happens the same, it is not from the transformer that I tried another new one, it is not from the simcard 2.0, this on the site, did anyone have an identical problem? the only solution I have and always leave it connected to the current in stand by so do not lose, but if I lack the current I have to install everything again.
thank you for help if possible
thank you