Hi guys, All of a sudden my 5 inch quad suddenly met this issue. It was completely working fine. No crash nothing.
Then when i connected the battery, the led lights came and went off quick before even hearing that power on tone. I unplugged and plugged again. This time the power on sound was incomplete playing only half. 3rd time when i plugged the battery, there was no sound too. It was mute. I even changed different batteries.

Tried connecting in Betaflight. But no surprise because it connects to FC directly. I confirmed there is no problem with the Flight controller atleast. Also no power on beep sound here too while connecting to PC through USB. No display in goggles too.
Connected Bheli. Even that too could not read it. It only said connect the power which i already done. However one help through bheli was, i got the log status.
Here it is:
(Earlier i flashed the firmware. But no use too)

sending cmd_InterfaceExit 0 0
Selecting last used port: COM7
Connecting to: COM7
SERIAL: Connection opened with ID: 1, Baud: 115200
Serial port <span style="color: green">successfully</span> opened with ID: 1
MultiWii API version <span style="color: green">received</span> - <strong>1.43.0</strong>
Flight controller info, identifier: <strong>BTFL</strong>, version: <strong>4.2.8</strong>
Running firmware released on: <strong>Feb 15 2021 12:08:36</strong>
Board: <strong>S405</strong>, version: <strong>0</strong>
Unique device ID <span style="color: green">received</span> - <strong>0x4a0049394e500420343942</strong>
Reading setup
sending cmd_DeviceInitFlash 0 0
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
ESC 1 read settings failed cmd_DeviceInitFlash ACK_D_GENERAL_ERROR
sending cmd_DeviceInitFlash 0 1
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
ESC 2 read settings failed cmd_DeviceInitFlash ACK_D_GENERAL_ERROR
sending cmd_DeviceInitFlash 0 2
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
ESC 3 read settings failed cmd_DeviceInitFlash ACK_D_GENERAL_ERROR
sending cmd_DeviceInitFlash 0 3
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
received cmd_DeviceInitFlash ACK_D_GENERAL_ERROR 0 0,0,0,0
ESC 4 read settings failed cmd_DeviceInitFlash ACK_D_GENERAL_ERROR
Reading setup <span style="color: green">finished</span>

Any ideas on this issue, guys?
Could be capacitor related? or ESC fried?

Thank you!