What Is a Monochrome Monitor?

Monochrome displays are black and white displays, as opposed to color displays. The earliest computer monitors were generally monochrome, with black and white and green. Only text can be displayed (early Chinese characters can not be displayed because it is a graphic method). Later, it supports grayscale, and graphics can be displayed with the support of graphics cards.

The display is also often called

Monochrome display circuits are divided into two types: independent line oscillation system and no independent line oscillation system.

Generally speaking, the display is mainly composed of the following circuits:

(1l)

Monochrome displays, as the name suggests, can only display a single color character or graphic when working. However, there are a variety of colors that can be displayed. The common ones are paper white, amber, yellow, and green. This type of display is suitable for text display. The figure below is a circuit diagram of a typical monochrome display.

The electro-optical conversion component of the monochrome display is a CRT black and white picture tube. The working process is as follows: After the CRT is powered up, the cathode is heated by the filament to emit electrons. A large number of electrons are accelerated away from the cathode under the attraction of the acceleration electrode and the anode. After focusing on an electronic lens composed of a focusing electrode, an anode, and the like, a very thin electron beam is formed and bombards the screen at a high speed. The phosphor layer on the screen emits bright light by the bombardment of electrons. The faster the bombarded electrons, the brighter the light emitted from the screen. However, what is the reason for the electron beam to run up and down and around the screen repeatedly? This is the current in the deflection coil that flows in a zigzag pattern. The sawtooth wave current generates an alternating magnetic field. Different deflection forces; row deflection produces a force that deflects the electron beam left and right, and field deflection produces a force that deflects the electron beam up and down. Because these two kinds of deflection force act on the electron beam at the same time, and show linear and periodic changes of positive and negative magnitudes, this high-speed electron beam constantly bombards the screen and traces (scans) the grating. ^[2]

Monochrome display repair skills are the basis for color display repair.

When the computer is turned on, there are no characters at all. First, check whether the monitor's 220V power supply and the signal cable connected to the graphics card are well connected, and whether the brightness and contrast buttons of the monitor are turned to the maximum position. Secondly, you should judge whether the display card is faulty or the display is faulty. The distinguishing method is that if the host speaker emits continuous beep, beep, and beep sounds after it is turned on, the display card is faulty. Open the main box and spray the I / O tank with clean cleaning solution. Or use a cotton ball to stick anhydrous alcohol to clean the contact spring between the graphics card and the expansion slot, or replace it with a slot. Unplug the video card. You must turn off the power of the host, and it is strictly prohibited to plug and unplug all kinds of cards and keyboards while the power is on. If there is still a continuous beep sound when changing the slot, you should try another video card. After replacing it with a trouble-free display card. The continuous beep sound disappears when the power is turned on, and there are still no characters, you should check the display. ^[3]