I. Hardware Composition of Industrial Control Motherboard
(I) Industrial Control Motherboard Chip Section
BIOS chip: The motherboard's basic input/output system programs are all located in the BIOS. It allows the motherboard to recognize each piece of hardware, configure boot system devices, and adjust the CPU's external frequency.
Southbridge chip: Located at the top of the PCI slot, it is responsible for the data flow between storage devices such as hard drives and the PCI slot.
Northbridge chip: Next to the CPU socket of an industrial computer, covered by a heatsink, is the Northbridge chip. It is mainly responsible for handling the communication between the CPU, memory, and graphics card. Because it generates a lot of heat, it needs a heatsink for heat dissipation.
The southbridge and northbridge are collectively called the chipset, and the chipset largely determines the functions and performance of the motherboard.
(II) Interface Section
PS/2 interface: PS/2 is an older interface used to connect keyboards and mice.
Industrial PC USB interface: The USB interface is currently the most widely used interface, which can support up to 127 peripherals and can be powered independently, making it very widely used.
LPT (Parallel Port): This type of interface is generally used to connect printers or scanners.
IDE interface: This is a general term for hard drive interfaces, which are divided into IDE1 and IDE2. IDE1 is used to connect hard drives, and IDE2 is used to connect optical drives.
Floppy drive interface: Used to connect floppy drives, usually located next to the IDE interface.
COM interface (serial port): Industrial control computers currently have at least two serial ports, such as COM1 and COM2, which are used to connect serial mice and other external devices.
(III) Insertion and Removal Section
PCI slots: PCI slots are milky white and can be used to insert devices such as graphics cards, voice cards, and data acquisition cards.
PCI-E slots: Unlike PCI slots, PCI-E slots are mostly black because PCI slots have a fixed length and are gradually decreasing in length, while PCI-E slots come in various lengths to better meet the different needs of users.
Memory slots: Memory slots are usually located below the CPU socket and are used to insert memory modules.
II. What are the reasons why the industrial control motherboard is not powered on?
What if the industrial control motherboard fails to power on during industrial computer use? Many consumers have encountered this problem. So what are the reasons? This article shares some common causes of industrial control motherboards failing to power on.
First, the appearance inspection:
2. Inspect the PCB of the industrial control motherboard for human-caused faults such as broken wires, chipped corners, or missing components. If such faults are found, repair the wires or replace the components first. The main areas to observe are the edges and back of the industrial control motherboard.
Second, measurements before the ATX power supply was plugged in:
1. Measure the 3.3V, 5V, 5VSB, and 12V voltages on the ATX power supply to check for short circuits to ground. Generally, the resistance to ground should be above 100 ohms. If the resistance is below 100 ohms, there may be a short circuit. If a short circuit is found, troubleshoot the problem by replacing the faulty components based on the specific voltage of the short circuit.
2. Measure whether the 12V power port on the 4-pin ATX connector is short-circuited to ground. If there is a short circuit in the 12V voltage, measure the MOSFETs in the CPU's PWM power supply section to see if there is any breakdown. In actual repairs, most of the time it is the upper MOSFET that is broken. We can first measure the resistance between the G and S terminals and the D and S terminals of the upper MOSFETs of each phase to determine which phase's upper MOSFET is broken and replace it. At the same time, it should be noted that, if conditions permit, it is best to replace both the upper and lower MOSFETs of the entire phase, and also replace the driver chip at the same time.
3. Measure whether the source (S) of each MOSFET on the industrial control motherboard that performs power conversion is shorted to ground, such as memory voltage VCC_DDR and AGP voltage VDDQ, and use this to determine whether there is a short circuit in the northbridge or southbridge.
4. Measure whether the standby voltages of 3VSB, 1.5VSB, and 1.2VSB on the industrial control motherboard are short-circuited. The most common problem is a short circuit in the 3VSB voltage. If this is found, first determine whether the network card is damaged. In addition to a short circuit in the network card, the southbridge is the most likely cause of a short circuit in 3VSB.
Third, measurements after plugging in the ATX power supply: After plugging in the ATX power supply, do not immediately power on the industrial motherboard for testing. Instead, measure whether some important operating conditions of the industrial motherboard in standby mode are normal. Here we need to introduce the concept of "Power Sequencing." Industrial motherboards have very strict requirements for power-on; various essential power-on conditions must be in a specific order, which is what we call "Power Sequencing." Only after one condition is met can the process proceed to the next step. If any part of the process fails, the entire power-on process cannot continue, and of course, the industrial motherboard cannot be powered on.
