For a newly designed circuit board, debugging often encounters some difficulties, especially when the board is relatively large and there are many components, it is often impossible to start. But if you master a reasonable set of debugging methods, debugging will be twice the result with half the effort. For the new PCB board that has just been brought back, we must first observe whether there are problems on the board, such as whether there are obvious cracks, short circuits, open circuits, etc. If necessary, you can check whether the resistance between the power supply and the ground is large enough.

Then there is the installation of components. Independent modules, if you are not sure to ensure that they work normally, it is better not to install them all, but to install them part by part (for relatively small circuits, they can be installed all at once), so that it is easy to determine the fault range, so as not to be unable to start when encountering problems.

Generally speaking, you can install the power supply part first, and then power on to detect whether the output voltage of the power supply is normal. If you are not too sure when powering up (even if you are very sure, it is recommended that you add a fuse, just in case), you can consider using an adjustable regulated power supply with current limiting function. The overcurrent protection current is preset first, then the voltage value of the regulated voltage power supply is slowly adjusted upward, and the input current, input voltage and output voltage are monitored. If there is no over-current protection and other problems in the process of up-adjustment, and the output voltage also reaches normal, then the power supply part is OK. Otherwise, disconnect the power supply, find the fault point, and repeat the above steps until the power supply is normal.

Next, other modules are gradually installed. Each module is installed, power-on and test it. The above steps are also followed when power-on, so as to avoid burning out components due to overcurrent caused by design errors or/and installation errors.