good day, sorry my English is not very good

I need help with my n900, we modify the kernel and has been completely dead,
performed the steps for a hard reset, but I detected n900, all steps are well made ​​hard reset, the phone on the screen is the USB symbol but does not start the flash, not q do please help.

hard reset on windows xp sp3 and windows seven 32 bit, but I've also used phonix nothing.
I've also tried flashing boxes with fbus