Problem with Electron

[internetserver]

Hello
I have a problem to flash the bootloader. My Electron shows only LED on D7.
I connected a P0 to the Electron and I checked everything several times.

But nothing happens:

Do you have a dead device and wish to continue? [y,N]:y
Unknown ACK (5) received.
Please double check the wiring, then try again.
Do you have a dead device and wish to continue? [y,N]:y
SWD Fault error
Please double check the wiring, then try again.
Do you have a dead device and wish to continue? [y,N]:y
SWD Fault error
Please double check the wiring, then try again.
Do you have a dead device and wish to continue? [y,N]:y
SWD Parity error
Please double check the wiring, then try again.
Do you have a dead device and wish to continue? [y,N]:y
SWD Parity error
Please double check the wiring, then try again.
Do you have a dead device and wish to continue? [y,N]:y
Unknown ACK (5) received.
Please double check the wiring, then try again.
Do you have a dead device and wish to continue? [y,N]:y
warning: unexpected idcode: 8ae8053f
SWD Protocol error
Do you have a dead device and wish to continue? [y,N]:y
Unknown ACK (5) received.

What is wrong? Is my Electron dead?
What means? "warning: unexpected idcode: 8ae8053f
SWD Protocol error"

Thanks for help

Nils