DM500hd dead

Hi

My brother's original DM500HD was discontinued without being shut down properly.
Since then it has not been able to start again.
When the power is switched on the LED is red and there is den.Ved pressure "Merely switching" flashes to green and returns to red.
It can not be contacted on the network and will have no IP router.
I can not contact it with the USB cable, but DreamUp and Optiflash get contact but then there will be no more.

Where do I start?

I have tried on the LAN, but the dream box will not reach far reaching that it takes up an IP from the router.
There will be no update screen when I hold the button and turn on the box. So the green diode and nothing happens
If I put the power on without holding the button turns red.
If I press the button flashes to green and back to red.

I do not know what it is for a bootloader and I picked up just rot that was linked to here, but I do not understand the bootloader properly.

Again, I can get in touch with DreamUp, but it ends with:

upload completed, waiting for acknowledge

so it ends.

I've tried with optiflash that I can choose the boot loader, but it goes into a loop and will not finish, so I can get to flash the image.

Yes, 3 different

But the problem is, I never extend below:

upload completed, waiting for acknowledge

Then DreamUp stuck, have tried with different versions.
OptiFlash goes in the loop and returns to "do job"