The below is my PS3 problem; bricked

The below is my PS3 problem;

I took a copy of 001000 file.
I copied bkpps3.bin file on my computer.
I put bkpps3.bin file on TF board from the sd card, and while all switches down 000000, I clicked start. However, it gave me an error and deleted bios.
My ps3 suddenly became brick.

I connected sbe test cable and opened ps3. I set the bkkpps3.bin file and TF board as 100000 and I downloaded it.
But after the flash fun, I did not get any hdd neither a signal on TV.
My question is that I could not return two ps3 after this point.
Is the flash fun process faulty?
I downloaded bkpps3.bin file correctly.
Is there any different process while downloading bkpps3.bin file?
What is the reason of this failure?
How should I do the backup process so I can fix the bricked PS3. I don’t want other PS3s having same problem!
Is there anything I can do to save these two PS3?
Thank you for your attention and help!