complex printed circuit boards

Summary: Due to the increased automation of production equipment, the number of production control panels in various industries has increased in recent years. The high cost of replacing circuit boards when factory dashboards are destroyed is a source of headaches for businesses. type. So, do you know any way to repair a printed circuit board? What are the steps to repair a printed circuit board? Next, let’s take a look at FS Technology’s printed circuit board maintenance knowledge.

FS Technology Online Measurement Method

In-line measurement methods are often used by manufacturers of mass-produced printed circuit boards. In order to facilitate maintenance, manufacturers generally build a more general debugging and maintenance platform, which can easily provide power and some required initial signals to the printed circuit board. The online measurement method addresses two main problems. The first is to separate out the problems identified in the first two steps, and finally to lock down the problematic item. Second, the two-step test did not solve the problem and required electronic measurements to determine the source of error. The online measurement method is mainly carried out through the following steps.

Step 1: Activate the toolbar.

It should be noted that at this stage, some power supply of the board may be required, such as 5V, plus or minus 12V, 24V, etc., because the power supply may not be autonomous. After connecting the circuit board, touch the components on the circuit board with your hands to ensure that there are no hot or hot components, and pay attention to check the 74 series chips. If the components are hot, the components may be damaged. After replacing components, inspect the tiles for damage.

Step 2: Make sure it fits logically.

If quitting doesn’t make sense, you should consider both cases separately. First, the output should be low and the actual measurement is high, which can instantly filter out chip damage. The second is that the output must be high, the actual measurement is low, and the chip cannot be damaged. It is also necessary to disconnect the chip from the next circuit, measure again, observe whether it makes sense, and judge the quality of the chip.

Step 3: Measure the crystal oscillator of the digital circuit with an oscilloscope and check the output.

If there is no output, the chip connected to the crystal should be removed as much as possible before measurement. If there is no output, the crystal is considered damaged. If there is an output, the damaged chips must be reset one by one, and a FS tech chip must be tested to find out the fault.

Step 4: Digital circuit with channel structure.

Generally consists of three channels: digital, channel and control. Use an oscilloscope to measure the three-way bus, compare the graphs, see if the signal is normal, and locate the problem. The online measurement method is mainly used to compare the quality of FS Technology’s printed circuit boards. Equations can be built to discover and solve problems. This completes the maintenance of the printed circuit board.