Monitoring Maintenance summarize: a conventional services 1. camera repair, replacement, installation, commissioning; 2. camera lens cleaner, dust, angle and sharpness adjustment; 3. monitor power lines and data transmission line maintenance, testing, and maintenance; 4. monitor, control maintenance panel, hard disk recorders, video splitter, matrix and other equipment, maintenance, installation and setup; 5. monitoring systems and equipment optimization: reasonable arrangements to monitor network monitoring center needs 6. monitoring lines, document finishing and records; 7. monitoring system changes, expansion, solution design and construction services. Access control systems deal with common problems and Symptom 3: Effective surveillance video card near the reader, the buzzer sounds for monitoring, LED indicators do not change, you can not open the door. Possible causes: (1) the connection between the reader and the controller is not correct; (2) the line of serious interference, data can not be transmitted to the controller card reader; surveillance video source maintenance (certified), monitoring provided by Zhengzhou source maintenance Electronic Technology Co., Zhengzhou source maintenance Electronic Technology Co., Ltd. (www.hnxywb.com) is a leader in Zhengzhou, integrated monitoring system, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In leading source maintenance staff warmly welcome all inquiries negotiations to create a better source of future maintenance.