Some customers report seeing a yellow flash in the upper right-hand corner of their screen(s) like this:
This means that the device is not getting enough power. If you see this, you will likely run into problems with stability. Common side effects of this include:
- Random reboots
- SD card corruption
- Network connectivity issues (in particular with WiFi)
You should replace the power supply with the official Raspberry Pi power supply for the Raspberry Pi 3 Model B / B+. Never use the TV to power the Raspberry Pi.