1. Signal interference problem: The striped background may be caused by unstable received signal. You can try to remove other electronic devices around the Dr device, especially those related to radio frequency, such as wireless phones and wireless routers. In addition, make sure the power and signal cables of your Dr device are well connected.
2. Ambient Light Interference Problem: The striped background can also be caused by the effect of ambient light on the Dr device. Try placing your Dr device in a dimly lit area to minimize interference from outside light. Also, make sure the Dr device's screen is clean and dust-free from dust and stains.
3. Display issues: If neither of the above is the cause of the problem, then there may be an issue with the Dr device's display itself. Try adjusting the monitor's brightness, contrast, and sharpness to see if it has an effect on the striped background. If the problem persists, it is recommended to contact Philips or the relevant repair service provider for advice and fix.
Please note that these are only some common causes and there may be other factors that can cause a striped background to appear. If the problem persists or cannot be resolved, please contact Philips customer service or a specialized technician for further troubleshooting and repair.