Error: target voltage may be too low for reliable debugging

[AhmedSayed]

i separated the debugger of my nucelo stmf401re from the rest of the board and i am using it to debug an stm32h750
but when i try to connect it with cube id i get those messages:
Open On-Chip Debugger 0.12.0-00017-gb153daa14 (2023-02-03-14:58) [https://github.com/STMicroelectronics/OpenOCD]
Licensed under GNU GPL v2
For bug reports, read
http://openocd.org/doc/doxygen/bugs.html
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : STLINK V2J41M27 (API v2) VID:PID 0483:374B
Info : Target voltage: 0.012615
Error: target voltage may be too low for reliable debugging
Error: init mode failed (unable to connect to the target)

the debugger is detected normally on the ide .
 i think there is a connection that i should make after breaking the debugger from the rest of the board is that right, and if so, what is it??

[FBL]

Hello @AhmedSayed 

Check the connections to the debugger. Try using CubeProgrammer to make sure the issue is not related to OpenOCD.

[AScha.3]

target voltage ...st-link want to know voltage here. try connect cn2 pin1 to vcc 3v3 on your target.