Hantek DSO2C15 about 37kHz impulse signal problem

pu6k1n

Look here https://4pda.to/forum/index.php?showtopic=1018961&st=4140

pu6k1n

The fact is that this frequency is generated by: 1. Switching power supply; 2. The converter powers the backlight of the LCD monitor.

pu6k1n

The first point can be eliminated by converting the switching power supply to a linear one; diagrams and photos are available on the specified forum. We cannot eliminate the second point. The root of your problem is probably a pulse source.