How Do I Choose the Best Cheap Motherboard?

Computer chassis motherboards are also called mainboards, systemboards, or motherboards; they are divided into two types: commercial motherboards and industrial motherboards. It is installed in the chassis and is one of the most basic and important components of a microcomputer. The motherboard is generally a rectangular circuit board, on which the main circuit system that composes the computer is installed. Generally, there are BIOS chips, I / O control chips, keyboard and panel control switch interfaces, indicator connectors, expansion slots, motherboards and cards DC power supply connector and other components.

Motherboards (English: Motherboard , Mainboard , Mobo for short), also known as motherboards , system boards , logic boards , motherboards , backplanes, etc., constitute complex electronic systems such as

The so-called motherboard structure is a general standard formulated according to the layout, size, shape, and power specifications of the components on the motherboard, which all motherboard manufacturers must follow.

The motherboard structure is divided into

in

AT: A standard-size motherboard. The IBM PC / A was named after being used first. Some 486 and 586 motherboards also use the AT structure layout.

Baby AT: Mini-sized motherboard, smaller than AT motherboard, hence its name. Many original machine integrated motherboards first adopted this

PnP function The motherboard with PnP BIOS and PnP operating system (such as Win95) can help users automatically configure the host peripherals to achieve "plug and play".

Energy saving (green) features generally have an Energy Star (

The failure of the motherboard often manifests itself as a failure phenomenon that is difficult to intuitively judge, such as system startup failure, no display on the screen, sometimes it can start, and sometimes it cannot start. When inspecting and repairing the failure of the motherboard, the maintenance principle of "one look, two listens, three smells, and four touches" is generally adopted. It is to observe the failure phenomenon, listen to the alarm sound, smell if there is a strange smell, touch some parts with your hands to see if it is hot, etc. The following is a list of several common motherboard repair methods. Each method has its own advantages and limitations. Generally, several methods are used in combination.

• The power line should be as short as possible and the line width should be as wide as possible;

• Avoid sharp and right-angled lines. Use 135 ° routing;

• Generally, the minimum line width is 4mil, and the minimum line spacing is 4.5mil;

• The high-frequency signal should be as short as possible, and the line should not hit VIA as much as possible, and it is not allowed to cross the cutting surface;

• When the distance between two solder joints is very small (such as the adjacent pads of a chip device), the solder joints must not be directly connected;

• The wiring and punching of the entire circuit board should be uniform to avoid obvious unevenness. When there is a large blank area in the outer signal of the printed board, auxiliary lines should be added to make the distribution of metal wires on the board basically balanced;

• Input and output signals should be avoided as much as possible, and parallel lines should be avoided. It is better to add ground between lines to prevent feedback coupling.