Use a spectrum analyzer to observe the radio frequency waveform of the remote control, place the receiving antenna of the spectrum analyzer near the receiver, and power the anti-theft system or receiver.
Waveforms or inverted V-shaped spectral waveforms should be observed in the frequency range of 200 to 400 MHz. If there is no reaction on the spectrometer screen, the receiver circuit is faulty and damaged. The receiver is installed within 1 meter of the left front door and can also be identified by maintenance personnel by measuring the voltage of the transistor and integrated circuit and comparing it with a normal remote key.
Under normal circumstances, the static current of the remote control is at the microampere level, and the current in the emission state is 5~10mA. If the current is too large or too small, it indicates a fault. The remote key is used to transmit signals, and the output of the receiver is observed with an oscilloscope. The input of the decoding circuit should have a pulse signal output. Because the transmitted data signals are different, the waveforms are pulse sequences with different widths and combinations of widths. If the waveform is abnormal or cannot be measured, there is a problem with the receiver.