The above reasons account for 50% of the non-vibration of the line, so the remaining 50% are the most critical factors: line oscillation and power supply failure before propulsion. The line oscillator circuit is integrated in the module 9370, and 8~9V power supply is provided by the 14 pin and the 39 pin. Measure whether the voltages of these two pins are normal. If it is not normal, check the previous stage, and you will soon find the culprit and solve the problem.
Tip: Generally, the 7808 three-terminal voltage stabilizing block is easy to be damaged.
I wish you success!