Frequency counter doesn't power on and reveals no indication of inner voltage existence. Teardown of the tool shows a huge PCB where all digital and analog circuity is included. The power distribution module is a module parts and upon dimensions shows no action.
The electricity source is a very simple switching architecture with working input rectifier and capacitor filter. By utilizing an oscilloscope it's apparent that the energy supply PWM controller tries to get started. On the other hand, the most important power source trap reveals unstable voltages indicating insufficient charge retention over the rectifying capacitor. The PWM control and chief switching transistors can also be replaced with fresh ones. Following this fix the device powers on and moves all self-tests.Frequency Counter China can successfully quantify signal power and frequencies.