Can not charge it anymore. Changed usb port but it doesn't work

Hello everybody. I have this issue with a RedRice 1s: after one year of excellent work, its charging port (micro usb) broke up: no charging, no connection with PC. I've bought a new charging board on ebay and I've changed it (it's easy!). Now I can connect the phone to the PC but I cannot charge my battery. (If I connect the battery directly to a current/voltage generator it charges).

Have you got any idea???