Analysis and elimination of incompatible fault between computer host and monitor

Said to be incompatible, the actual fault is not a true sense of incompatibility, only from the symptoms of failure and language expression on the use of the word "incompatible" is more appropriate. This failure is not uncommon, with the computer more and more time to use, monitors and mainframe components are also slowly aging, capacitance capacity in the slowly become less, resistance will have some changes, then there may be some inexplicable fault, to our maintenance bring great trouble.

Here are a few examples to illustrate how we can solve such failures.

1, in the use of the screen in the process of irregular appearance "frequency out of range" after the black screen

A computer is assembled, the display is a grand Hisap 7002E 17-inch CRT flat-screen display. Failure performance is often in the boot or when the game screen to switch on the CRT screen display "Frequency out of range" information, after a while the monitor black screen can not use the computer. Sometimes restarting a computer monitor can occasionally return to normal, and most of the time after the restart is invalid.

Customers repeatedly repair, maintenance staff after the door also did not find problems, while providing customers with proxy display no problems. Drag the customer's monitor back to the company, join the test with the other host, use display mode, test and change the refresh rate, and the failure never occurs. Because the customer's machine fault is more special, monitor maintenance staff on the monitor boot check, also can not find problems.

In order to avoid customer repair again, for customers to replace a new monitor, the failure to solve.

2, monitor irregular appearance of black screen

An old CII850 computer, the graphics card is I740 8M, the motherboard is via chipset, and the monitor is a patriot 700H 17-inch flat screen display.

Failure performance: The machine has been used for nearly six years and has been used normally. After the customer due to work needs, the machine moved to a construction site, the site environment is more complex. Recently appeared every morning, can hear the host normal start "beep" of a sound, but the display has no image display. In order to solve the problem, the customer carries the monitor and the host to the company to carry on the maintenance, the on-line use is normal when the test, and then connects the host with other monitors to be normal; it is normal to connect the customer's monitor to other hosts.

Initially suspected that the power supply performance caused by the output of the video card line frequency and the frequency and the monitor is not synchronized, for customers to replace the power supply, the normal use of three days, after the same failure occurred. In the troubleshooting of the display and video card, in order to operate conveniently, first for the customer to replace the graphics card, the day sent to the good, the next day when the failure occurred.

After the customer purchased a second-hand monitor after troubleshooting.

3, the screen image jitter is serious

Grand 15-inch, 17-inch LCD with Hua-chi m266a motherboard assembled computer.

Failure performance: Because Hua Qing m266a motherboard is integrated with a graphics card. When the integrated graphics card is used, the whole screen image of the LCD screen is clearly flashing and occasionally the whole screen image is dithered. Replace the other brand LCD or CRT monitor did not find this fault, the replacement of independent graphics with a grand display also did not find this issue.

4, the monitor respiration effect is very obvious

Machine configuration: Motherboard Elite L41BMGL2, Memory hy128mddr, hard disk ibm40g,cpu for civ1.7g, power supply Da Yu ATX-300WB & P4 V2. 3 version, TCL M505 CRT monitor.

Failure performance: When you open a window or close the window, the display screen changes very clearly, that is what we usually call the "respiratory effect", the image edge to a large range of nearly 5MM, the computer is not normal use.

During the inspection, it was found that the monitor was connected to the other host and no respiratory effect was found. Connecting the client's host to other monitors did not detect respiratory effects, as there was no test for the same brand of the same type of monitor. Therefore, the display itself does not have the quality of the total, the cause of the failure should belong to the case, a compatibility failure.

To replace the monitor for the customer after troubleshooting

5. Burn the display when repairing

The customer sends the Tsinghua Tongfang host, uses the HISAP 17 inch 7002D CRT display in the overhaul.

After the connection is correct, add the electric test machine, when the system just entered the desktop, the monitor smoke after the black screen. Replacement of other monitors, the host started normal, customer repair is a software failure, can not access the Internet.

Failure Reason: The customer uses in the home display performance to be good, the resolution and the refresh rate setting is high, but the HISAP display is the low-grade product, the bandwidth is low, simultaneously also did not have the good protection measure. When the monitor receives the high resolution and high refresh rate sent by the host, it exceeds the normal working range of the display, reaches the limit of FBT, and causes the line scan related circuit element to overheat and burn smoke damage.

This is one of the ways software settings can destroy hardware.

6, causes the problem the main reason analysis

At present, the interface between computer and monitor used more or 15-pin VGA interface, where R, G, b three-color information transmission is analog information, through the RGB three-color signal strength, and line-field synchronization signal to jointly realize the color and brightness combination of the image. When we set power-saving options in CMOS, one of the settings for the monitor (video off method) is the option to turn off the monitor's power supply based on the line or field signal. If the host does not send the line or the field signal even if there is RGB three-color signal, the monitor will not have images appear. However, if the monitor is not able to sync with the line-field signals sent by the host during use, the display will not have an image.

The above examples of failures are very typical, are with the host sent to the field signal strength and signal polarity is related. The monitor is receiving a line signal number from the video card, to first select the working mode (resolution) of the display according to the polarity of the field signal ("Ten" or "-"), while the MPU of the display will capture the line signal and the field signal, forcing the display to work in the line frequency and field frequency of the video card. Work on the resolution and refresh rate set by the host.

If the monitor is unable to sync with the line-field signal sent by the video card or to catch the row-field signal error due to interference or the same frequency variation of the line field, the monitor will appear black screen or other unexpected fault, as described in the example above.

7, the solution to the problem

1. New Machine

If this is the case with the new purchase machine, it should be judged to be incompatible, we can choose to replace the video card or motherboard, can also replace the monitor to resolve this issue.

2. Old Machine

If the machine is in use for several months or years after such problems occur, is generally the internal display of components aging or graphics components aging caused, generally we can use the replacement method, and finally to replace the lowest value accessories as well.

For the upcoming DVI interface, because the use of digital signal transmission, for the line frequency and field frequency signal is the use of analog and digital simultaneous transmission, the general can ensure that the monitor accurately capture and maintain synchronization with the host, will not appear above the abnormal situation