Revert firmware of ST-Link of NUCLEO-L053R8

[p80]

I tried to modify firmware of ST-Link of NUCLEO-L053R8 using a tutorial.

However, when I select CMSIS-dap in Keil (as mentioned in tutorial) it says "not a genuine ST device abort connection". Everything worked well before modification.

Now I want to revert to original firmware but STM32 ST-LINK Utility doesn't detect board.

When I connect board to PC, LD1 is green and LD3 turns on for a moment and then turns off. After trying to use CMSIS-dap and getting error, LD1 turns red.

How should I revert to original firmware or bypass "not a genuine ST device" error?

[p80]

OK. Found the solution here.

After connecting board to PC, do a short circuit between RST and SB11 pads (under ST-Link part of board); PC will detect ST-Link. Then perform a firmware upgrade by STM32 ST-LINK Utility.