Default Xperia V stuck on fastboot

Hello,
Recently my phone dropped and half of my touch screen stopped working. I have disassembled my phone just to try if the old lcd will work when I plug the connector out and in again. I discovered that no so I have ordered the new LCD. During the reparation I accidentally broke coaxial cable between the antenna and motherboard so I ordered the new one. Now phone worked, but there was no phone signal but display and everything else worked just fine. I have disassembled the phone again when the new coaxial cable arrived but I have discovered, that I have bought bad one because it did not work. So I left the phone disassembled and wait for another one.

After I assembled the phone with the second coaxial cable my phone does not show nothing on the screen, even on the old LCD. When I connect phone to the pc I got instantly to the fastboot and I can get out of it. After fastboot reboot I get again to the fastboot.
Sometimes the LCD powers up but does not show nothing, and when the phone is in the charger the diode is red.

Does anybody have any idea how can I fix this problem?
I have tried to boot the phone without camera, speaker, antena, but nothing worked.