(1) Button Description:(A key) Direct, directly measure the button (far away from the LCD screen), that is, when using the pen tip to directly contact the circuit, please press this button.

The voltage range for testing with a test pen is usually between 60 and 500 volts.The test pen consists of a metal body at the tip of the pen, a resistor, a neon tube, a pen body, a small window, a spring, and a metal body at the end of the pen.