I. "Consulting printers"
In the printer family, needle printers, inkjet printers and laser printers are still the main types. Among these three types of printers, the service life of needle printers is generally longer, followed by laser printers, and the service life of inkjet printers is relatively short. This is mainly due to the different internal structures of different types of printers. Of course, service life is also related to daily use and maintenance methods.
1, structural principle
Before the "consultation", let's make preparations and talk about the structure and principle of various printers. Needle printer (also called dot matrix printer), as its name implies, uses the dot matrix striker in the print head to hit the printing ribbon to produce printing effect on the printing paper. This structure is easy to cause needle breakage, and in addition, it is often necessary to replace the ribbon.
The inkjet printing technology of inkjet printers is mainly divided into two categories: continuous inkjet printing and intermittent inkjet printing. Continuous inkjet printing technology is rarely used now because of its complex structure and high cost. At present, intermittent printing technology is popular, which is divided into "hot bubble type" and "piezoelectric type". Hewlett-Packard and Canon both adopt hot-bubble structure. The basic principle is that the ink in the ink-jet head is heated rapidly by using resistance, so that the ink vaporizes and bubbles are generated, and the bubbles expand to spray the ink out of the nozzle, and the ink drops are sprayed on the paper at a speed of 3000 to 6200 points per second. When the distance between the nozzle and the paper is small, Epson adopts another technology, which is called "Piezoelectric" and adopts the technology of multi-layer piezoelectric structure (MACH). It has achieved great success in storing and exciting the air chamber structure of inkjet and the ink change caused by the high temperature of current pulse resistance, making the ejection force greater, the ejection speed faster and the printed image finer. Even if magnified several times, it is still very compact and regular. Due to the particularity of the nozzle, the service life of the nozzle is longer. Epson also said that the heating method was OK in the era of black-and-white printing, but it became a problem in color printing, because the chemical characteristics of black water changed when the temperature changed, so the color stability was poor, while multilayer piezoelectric printing did not have this problem. The nozzle can be made very small, and the ink jet speed is faster, which improves the printing speed and printing accuracy. Due to the precision of the nozzle, attention should be paid to maintenance during use to avoid blocking the nozzle.
The laser printer consists of three parts: laser scanning system, electronic photography system and control system. The laser scanning system includes laser, deflection modulator, scanner and optical system. Its function is to form an electrostatic latent image by scanning a laser beam. An electrophotographic system consists of a photosensitive drum, a high-voltage generator, a developing and fixing device and a paper feeding mechanism. Its function is to convert electrostatic latent image into visual output. The printing principle of laser printer is similar to that of electrostatic copy, but the difference is that electrostatic copy scans the original with visible light to form a latent image, while laser printer scans the information output by computer with modulated laser beam to form a latent image.
2. Basic methods
In general, printer failure is nothing more than hardware failure or software failure, which can be judged by hardware method and software method respectively.
The so-called hardware method, first of all, uses the printer's self-checking system to detect, which may be judged by the printer's own indicator light or buzzer sound, in which the indicator light can indicate the most basic faults, including paper shortage, ink shortage and power shortage. The judgment of buzzer mainly depends on your hearing. For example, most printer buzzers use long beeps to indicate that they are ready to start printing, and short beeps indicate that the printer is out of order. Secondly, we can observe the lines, starting with the detection of the printer cables (including the detection of ports, channels and printing lines), and then analyze the internal structure of the printer (including the paper holder, paper inlet and printing head). ) See whether the components are working normally, lock the related components according to different fault conditions, and then determine the problematic components. Third, you can use the test method to print a test page or partially test the internal components of the printer to see the cause of the failure.
Software method refers to checking the working state and related faults of printers with software. Usually, some relatively perfect printer drivers will have their own printer detection software, which is convenient for users to find related faults during use. Another commonly used printer fault help file in Windows can find a lot of relevant information. In addition, there are some external printer detection programs, whose working principle is usually to narrow the fault range through question and answer, or just to detect the print port, which has limited practical value. It is worth mentioning that many times software failures can be solved by upgrading the driver or visiting its website.
3. Practical skills
In the process of using printers, the problems we often encounter are nothing more than several situations. Let's analyze it below. I hope everyone can master the method and draw inferences from others.
1) illegible handwriting:
Whether it is a stylus printer, an inkjet printer or a laser printer, this situation is usually related to hardware failure. We can pay attention to the key parts of the printer through line observation. Take an inkjet printer as an example. If the printed matter is blurred in color and font, you can lock the nozzle failure and automatically clean the print head first (according to the instructions). If it is not used for printing for a long time, it should be cleaned several times. You can also carefully remove the ink cartridge and clean the area near the print head with soft absorbent paper. If it can't be solved, it may be a driving problem. Generally, it is enough to reinstall the printer driver.
2) The printing effect is different from the preview:
When editing a file with word or wps2000 and printing it with a printer, it is obvious that the words in the preview are neatly arranged, and there may be some overlapping words on the printing paper. This phenomenon is generally caused by improper settings when editing. Generally, it can be solved by changing the paper size, paper type and words per line in the Page Properties of the file.
3) After the print command is issued, the printer does not respond:
We often encounter this situation, usually the system will prompt you to check whether the printer is online and whether the cable connection is normal. After inspection, if the reason is that the printer's power cord is inserted incorrectly, the printing line is poorly connected or contacted, and the computer's parallel port is damaged, first press the printer switch to see if the printer can be started. If it can't start normally, the power light won't light up. First, check whether the power cord of the printer is correctly connected with the power supply and the power socket at the back, then plug the power cord again after turning it off, and try to plug it into another power socket to see if it can be solved. If it still doesn't work, try another thread, if it still doesn't work. We must contact the dealer. If the printer can start normally after pressing the print power switch, enter BIOS settings to check the parallel port settings. General printers use ECP mode, and some printers do not support ECP mode. In this case, you can use ECP EPP or "Normal" mode. If the problem has not been solved, check the print line, first turn off the computer, unplug the print line from the parallel port behind the host and plug it in, then unplug the other end of the print line from the parallel port behind the printer and plug it in again, taking care not to plug it in with electricity. If the problem cannot be solved, please try to replace the print cable or use other methods.
4) The printer and computer cannot be connected:
In fact, this kind of fault is a bit similar to the fault just now. Just now we focused on solving it with hardware. Now, we will introduce software solutions to software failures. This fault is manifested as the printer is not online after the host starts, the host is deadlocked when printing files, or the printer is unresponsive. In most cases, this is not a hardware failure of the printer. You can try to use software to determine whether there is virus infection first. Find a clean antivirus floppy disk to start the computer from the drive, and check whether the printer and the host can be connected at this time. If you are online normally, it is estimated that this fault is caused by a virus that attacks the performance of hardware devices. You can run the latest anti-virus software for anti-virus treatment and troubleshooting. If you still can't surf the Internet after starting from disk A, you can check whether the address setting of the print port has changed. The method is to start the machine again, enter the CMOS setup program, and check the setup status of the printer parallel port LPT 1. Its normal setting should be "Enable" and the parallel port address value is 378H. Of course, it can also be set to automatic.
5) Printing large files crashes:
Some laser printers print small files normally, while printing large files will crash. This is obviously a software failure. You can check the remaining space on the hard disk, delete some useless files, or check the printer's memory and see if it can be expanded. Now the memory is so cheap.
6) Individual fonts cannot be printed:
This is also a software fault. Sometimes, several commonly used fonts and sizes are always in use. Recently, I changed several fonts, and found that the fonts could not come out at all or individual words were gone. You can delete the problematic fonts before processing. Delete Font First select a font, and then select "File = >" to delete the previously unused font. Then double-click My Computer Control Panel = > Fonts = > File = > Install a new font.
7) Only partial printing or incomplete printing:
If it is judged that it is caused by a software failure, you can change the printing interface settings in Windows95/98, and then select Start/Settings/Control Panel/System/Device Management/Ports/Printer Ports/Drivers/Change Drivers/Show All Devices to change the ECP printing port to a printer port and confirm.
The key to solve the printer fault is to observe the fault location, then find out the cause of the fault, and then deal with it by hardware or software. After constant practice, you can master more skills of "consulting printers".
Second, "consulting scanner"
The former hand-held scanners and roller scanners are not the mainstream of the market now, and flat-panel scanners are still popular. In terms of service life, the flat scanner is the longest, followed by the roller scanner, and the service life of the handheld scanner is relatively short. This is mainly because these three scanners have different internal structures and different ways of use.
1, structural principle:
The working mode of the scanner is to illuminate the manuscript or picture with a light source to generate high-brightness reflected light. The light passes through the reflecting mirror and the transmitting mirror, is separated by the spectroscope, and shines on the CCD (Charge Coupled Device) element. The CCD converts the light signal into an electrical signal and transmits it to the computer. Therefore, the key accessory of scanner is CCD, and its performance directly affects the performance of scanner.
The scanner is mainly composed of photosensitive devices, high-power fluorescent tubes, driving motors, transmission belts and analog-to-digital signal converters. The work of the photosensitive device is to convert the sensed optical signal into an electrical signal. Illuminate characters or images in strong columns with high-power lamps to achieve complete induction. The function of the driving motor is to drive the fluorescent tube, so that the light can sweep the needed articles step by step. The driving belt is a device that is brought to the fluorescent tube together with the driving motor. An analog-to-digital signal converter converts analog electrical signals into digital signals recognized by a computer.
2, the basic method:
No matter what kind of scanner it is, there are bound to be various types of problems in use. We divide these problems into hardware failures and software failures. Common hardware faults include too much noise when scanning, and the scanner is not powered on. Common software faults include unclear scanned images and slow scanning speed. No matter what kind of fault, there are corresponding solutions, which can be software methods or hardware methods. Usually, software methods are easier to handle, while hardware methods often rely on some tools or even specialized maintenance personnel.
The method to determine the fault can be to observe and observe the cause of the fault, and to determine that the fault part, such as the scanner, is unresponsive, and whether the power cord is connected properly can be considered. It can also be a testing method, which can determine the problematic place through testing, such as scanning a picture and finding that the scanned image is not clear enough. There is also a screening method, which can further determine the fault location when several components that may cause faults are found by observation. Sometimes, through more methods, the source of the fault can be determined and then the solution can be sought.
3. Practical skills
Similarly, in the process of using scanners, we often encounter several types of problems. Let's analyze these failures, and hope that everyone can master some of them.
1) Scanner not found:
I believe this is the most common problem. First observe whether the power supply and line interface of the scanner are connected properly, and then confirm whether the power supply of the scanner is turned on before starting the computer. If not, you can press the "Refresh" button of Device Manager to check whether the scanner has self-check and whether the green indicator light is always on. If the answer is yes, we can rule out the possibility of the scanner itself. If the indicator light of the scanner keeps flashing, it means that the scanner is not in a normal state. At this point, you can reinstall the latest scanner driver. At the same time, check whether the scanner in the device manager conflicts with other devices (IRQ or I/O address), and change it if there is any conflict. Remember, this kind of fault is nothing more than line problem, drive problem and port conflict problem.
2) There is a lot of noise during scanning;
It is normal for a flat-panel scanner to drive the scanning part by mechanical rotation, and it produces certain noise, which is usually closely related to the scanning speed. According to the specific software of each brand machine, setting the scanning speed to medium or low speed can solve the problem. In addition, if the lubrication between parts is not enough, some lubricating oil can be added appropriately.
3) The scanner is not ready:
After turning on the power of the scanner, if the ready light does not light up, first check the internal light of the scanner. If the internal light is found to be on, it may be related to the room temperature. The solution is to turn on the scanner for half an hour and then turn it off. Open it again in a minute and the problem will be solved. If the scanner still doesn't work at this time, please turn off the scanner first, disconnect the scanner from the computer, set the value of SCSI ID to 7, and then turn on the scanner after about one minute. When the temperature is low in winter, it is best to preheat it for a few minutes before using it to avoid the phenomenon that the ready light does not light up after booting.
4) The color of the scanned picture is blurred:
First, check whether the flat glass on the scanner is dirty by observation. If yes, please wipe the glass with a clean cloth or paper, and be careful not to wipe it with alcohol and other liquids, which will make the scanned image appear rainbow color. If it is not glass, please check the resolution used by the scanner. For example, the image scanned by a 300dpi scanner will be blurred if it exceeds 1200dpi. Because a 300 dpi scanner scanning 1200dpi is equivalent to quadrupling one point. In addition, please check whether the monitor setting is 16-bit color or above. If you scan some printed matter, it is understandable that there is a certain amount of moire. The processing method can be processed by the scanner's own software, or by image software such as PHOTOSHOP.
5) The color of the output image is not gorgeous enough:
This is also a software fault. You can adjust the brightness, contrast and gray value of the display first. Gamma value is the feeling curve of human eyes from dark color to bright color. The higher the gamma value, the richer the level of color perception. We can adjust the Gamma value in the scanning application software that comes with the scanner. Of course, in order to get better results, you can also adjust the Gamma value in Photoshop and other software, but this is an "after-the-fact adjustment". We can adjust the Gamma value according to the specific situation of scanned photos. In the software that comes with the scanner, if it is for general use, the Gamma value is usually set to1.4; If it is used for printing, it is set to1.8; The photo on the web page is set to 2.2. In addition, the scanner should be color corrected before use, otherwise it is likely to distort the scanned image; In addition, you can specifically adjust the brightness/contrast options in the scanner driver dialog box.
Scanner problems usually come from scanning effect, which is often one of software faults. For these software failures, different scanners have different solutions, and using related software to correct them is one of them. Hardware failures are mainly interface and line problems. As long as you connect the lines, set up the ports and use the latest drivers, these problems should be easily solved.
Three. This article outlines:
It is not difficult to find that no matter whether the scanner or the printer fails, it is necessary to observe the faulty components according to their structural principles, and then analyze the reasons and find out the corresponding solutions. Moreover, experience plays a great role in troubleshooting, so we should accumulate more experience. If you buy a product with good after-sales service, you can call the agent or manufacturer directly to ask, and the problem may be solved. Of course, we should also have a little DIY spirit and try to solve some problems, which is exactly what this article wants to teach you.