2019-09-01 11:00 PM
Error in initializing ST-LINK device.
Reason: Failed to connect to device. Please check power and cabling to target.
Reason: ST-link DLL error
Reason: USB communication error
2019-09-01 11:54 PM
I guess you have destroyed your board, judging by the little information you provided.
> please give solutions
This is not ST's customer helpdesk, but a forum, populated mostly by unaffiliated engineers and users.
Such a demanding posture is usually not too well received.