If your phone is stuck showing as "SPRD U25 Diag" and won't turn on, it may be because a service tool forced it into a permanent "BROM" or diagnostic state. To resolve this:
(often listed as SPRD U2S Diag COM Port) is a specialized Windows communication driver designed for mobile devices powered by Spreadtrum (now UNISOC)
The is a specialized communication driver used for servicing mobile devices powered by Unisoc (formerly Spreadtrum) chipsets. It establishes a "Diagnostic" (Diag) COM port connection between a PC and a mobile device, typically for tasks that require deep system access. Core Functions
