shutdown waveform does not disappear

Packaging list:

15001K (SMD components welded):

All parts of the shell oscilloscope, including the analog board mounting components, have been soldered
Package Includes: 1Pc DSO Shell Oscilloscope
Versatile and Convenient: The DSO Shell Oscilloscope offers a range of features including adjustable vertical displacement, multiple coupling methods, and various trigger methods. It also has a digital display with waveform parameters for easy analysis.

High Precision and Sampling Rate: With a precision of 12 bits and a maximum real-time sampling rate of 1Msps, this oscilloscope ensures accurate and detailed waveform measurements.

Wide Frequency Bandwidth: The analog frequency bandwidth of 0-200KHz allows for the observation and analysis of a wide range of signals.

Convenient Packaging: The package includes all the necessary components of the shell oscilloscope, making it easy to set up and use right out of the box.