After purchasing new, I only tested it and confirmed it was working, then stored it. Upon listing, I checked the operation and found that the transmitter's green light was rapidly flashing, and the battery could not be charged. The outer box has some damage. I was able to confirm that the receiver and transmitter powered on. This is a junk item, so please understand and consider this before purchasing. I contacted SHURE support, and they said: - Battery protection function is enabled If the battery has not been charged or discharged for a long period, the battery protection function may automatically activate. This protection function can be解除 by charging with a GLXD4 or GLXD4R. - Battery failure If the protection function does not activate and the battery continues to over-discharge, the battery may be faulty. In case of failure due to over-discharge, the battery needs to be replaced. - Transmitter GLXD1 charging function failure If the GLXD1's charging function is faulty, charging may not occur normally, and the symptoms you reported may occur. If the transmitter is faulty, repair is required.