How Do You Debug a New PCB?

Debugging new printed circuit boards can be

difficult, especially if the board is large or has many long components. The startup process may also

encounter problems. If a reasonable and scientific debugging method can be mastered, debugging will

become much more effective.

The first task for newly received PCBs is to

inspect the board for defects, such as cracks, short-circuits, open-circuits, etc. Check if the

resistance between the power wire and the grounding wire is within safety standards.

The next step isthe installation of the components. If you’re not sure if the stand-alone module

will work, you should install the circuits in smaller parts.

is usually installed first and tested after the power has been turned on. It is recommended that you add

a fuse even if your confidence level is high. Use an adjustable voltage power source with a

current-limiting feature. The current setting should be greater than the current protection level. The

voltage of the voltage stabilized power supply should then be gradually increased, while the input

voltage, input current and output voltage are monitored. The power supply can be qualified if there is

no overcurrent trigger and the output voltage reaches a normal level. The power supply must be

disconnected and the fault found. This process is repeated until the power part is fully normal.

Install other modules, one by one, after. Make sure that each module has been installed correctly.

Perform power-on tests and follow the steps to check power.

There Are Many Ways to Troubleshoot Errors:1. Voltage Measurement Method

Check the working voltage and the reference voltage at each pin. When a silicon transistor is switched

on, for example, the BE junction is around 0.7V and the CE junction is around 0.3V. The BE junction

voltage is higher than 0.7V for a transistor (except in the case of special transistors like Darlington

transistors). The BE junction can be disconnected if the transistor’s BE voltage is greater than

0.7V (except for special transistors such as Darlington transistors, etc.

2. Signal Injection Method

Connect the source of the signal to the input terminal, and measure each waveform to determine if it is

normal. This will help you find the fault. We can use simple methods, like using tweezer to touch the

layers to see if there is a response. This method should only be used on high voltage circuits and

heating circuits. If there is no output response on the first layer, but there’s a response on the

second, then the problem is at the previous level. This should be the main focus of the inspection.