Arduino Burning Bootloader Error

Official Hardware Mega Mega 2560
1

I've tried everything but I haven't found a solution, please help.
My device is a custom mega with an Atmega2560 chip.
It was working normally, and I accidentally tried to flash the bootloader without supplying 5V, and this is the result.
Here is the detailed error:

Using port            : COM5
Using programmer      : stk500v1
Setting baud rate     : 19200
AVR part              : ATmega2560
Programming modes     : SPM, ISP, HVPP, JTAG
Programmer type       : STK500
Description           : Atmel STK500 v1
HW Version            : 2
FW Version            : 1.18
Topcard               : Unknown
Vtarget               : 0.0 V
Varef                 : 0.0 V
Oscillator            : Off
SCK period            : 0.0 us
XTAL frequency        : 7.372800 MHz

AVR device initialized and ready to accept instructions
Device signature = 00 00 00 (retrying)
Device signature = 00 00 00 (retrying)
Device signature = 00 00 00
Error: invalid device signature
Error: expected signature for ATmega2560 is 1E 98 01
  - double check connections and try again, or use -F to carry on regardless

Avrdude done.  Thank you.
Failed chip erase: uploading error: exit status 1

I checked the connections and while I can flash a bootloader into other devices, I can't flash one onto this one.

Please help, and thank you in advance.

2

Have you considered the possibility that doing so has physically damaged the chip and it's game over?

3

Unfortunately it looks like that