When Rework Heidelberger Optical Lithographic Equipment Controller Card, Static Measurement is one of the most commonly used method for the preliminary inspection over the device:
For most machine controller boards, previous observation methods failed to detect the problem. As long as a small part of the printed circuit board is physically deformed for some special reason, it is easy to find the cause of the failure. Most faulty PCB boards still require a multimeter to have some major components and key points on the board. Orderly measurement, find problems, solve problems.
Before making a static measurement, first determine if the controller circuit is dominated by an analog or digital signal. For electronic pc board with schematics, you can judge by looking at the schematics. But for a circuit board without a schematic diagram, you can think of restore schematic diagram from existing PCB board, and/or you can usually judge by the following two methods:
FIRST: Observe the components on the circuit board to see if there is a microprocessor on the it, whether it is an earlier version of the 80, 51 series, or now Has been widely used for the application of DSP and FPGA, as long as this chip appears on the PCB electronic board, it means that there is a bus structure on the board, and digital signals will occupy a large part, and it can be regarded as a digital PCB board.
SECOND: For a electronic controller card without a microprocessor, observe the components on the it and confirm that there are not many chips using 5V power. If there are many 5V power chips, they can also be repaired as digital circuits. Digital and analog circuits motor boards are maintained differently. It is usually easier to repair analog control board circuits. You can deduce the problem step by step.
