1e41f4b71Sopenharmony_ci# Brightness Error Codes 2e41f4b71Sopenharmony_ci 3e41f4b71Sopenharmony_ci> **NOTE** 4e41f4b71Sopenharmony_ci> 5e41f4b71Sopenharmony_ci> This topic describes only module-specific error codes. For details about universal error codes, see [Universal Error Codes](../errorcode-universal.md). 6e41f4b71Sopenharmony_ci 7e41f4b71Sopenharmony_ci## 4700101 Service Connection Failure 8e41f4b71Sopenharmony_ci 9e41f4b71Sopenharmony_ci**Error Message** 10e41f4b71Sopenharmony_ci 11e41f4b71Sopenharmony_ciFailed to connect to the service. 12e41f4b71Sopenharmony_ci 13e41f4b71Sopenharmony_ci**Description** 14e41f4b71Sopenharmony_ci 15e41f4b71Sopenharmony_ciThis error code is reported if a service connection failure occurs. 16e41f4b71Sopenharmony_ci 17e41f4b71Sopenharmony_ci**Possible causes** 18e41f4b71Sopenharmony_ci 19e41f4b71Sopenharmony_ci1. The system service stops running. 20e41f4b71Sopenharmony_ci 21e41f4b71Sopenharmony_ci2. The internal communication of system services is abnormal. 22e41f4b71Sopenharmony_ci 23e41f4b71Sopenharmony_ci**Solution** 24e41f4b71Sopenharmony_ci 25e41f4b71Sopenharmony_ciCheck whether the system services are running properly. 26e41f4b71Sopenharmony_ci 27e41f4b71Sopenharmony_ci1. Run the following command on the console to view the current system service list: 28e41f4b71Sopenharmony_ci 29e41f4b71Sopenharmony_ci ```bash 30e41f4b71Sopenharmony_ci > hdc shell hidumper -ls 31e41f4b71Sopenharmony_ci ``` 32e41f4b71Sopenharmony_ci 33e41f4b71Sopenharmony_ci2. Check whether **DisplayPowerManagerService** is included in the system service list. 34