I connected STM32F401CCU6 board and ST-LINK/V2 with a SW called STM32 ST-LINK Utility. I'm sure it worked yesterday, but I don't know why it doesn't work now. The screen keeps saying "ST-LINK USB Connection Error" and plug in the USB and refresh, it will be connected for a while, and if I refresh, it won't be connected, so I think I'm going to lose my mind right now. I don't know what the problem is, what should I do?
Can you test your ST-LINK on another MCU to make sure that it works fine. If so, use another ST-LINK and with your MCU. Also, try to look if it is an ST official product or an imitation. For imitation products, it can be a few unexpected problems. Finally, don't forget to check your USB cable and the USB port of your PC.
symtom: sometimes working - sometimes not - right?
this is almost usb-cable or connection problem . so try different cables, at different usb outlets.
and use stm32CubeProgrammer , not link utility (this is deprecated ).
and dont use old, worn out cables/plugs.
what should i (we) tell you?
i know almost nothing, just that you tried under unknown conditions, to connect to F401 with a deprecated software.
so: what is your PC/system , st-link , board with F401 ? condition: new? did it already work/connect?
use stm32CubeProgrammer now? tried different cables, at different usb outlets ?
I will attach the image of my cell phone using two different computers. Please understand.
I don't know if you can see it well in the picture, but I'm connecting with ST-LINK/V2 using STM32F401CCU6 board by referring to other YouTuber videos and using "ST-LINK Utility" SW. Yesterday, when I connected with a fake product, it went well, and now I replaced it with a genuine product and ran it, but I can't read the STM32 (Target) although the USB Connection Error doesn't come out. Do you understand me?