Talk about the common troubles and elimination of needle printers

In the process of using the dot matrix printer, some failures may occur. Xiao Bian summed up some of the problems encountered in the use and maintenance of the printer and troubleshooting methods.

First, the printer does not move paper

First, make sure the printer paper is installed correctly on the chain feeder or on the paper feed platform; if it is all right, check whether the print mode is selected single page or continuous mode.

Second, the printer to go blank paper

The reason may be that the ribbon is dry or not stuck in the correct position, or the number set by the paper thickness adjustment lever is too large, which affects the contact between the print head and the platen, and the plain paper should be adjusted to “1”. .

Third, the print character is not complete or the character is not clear or the word is light

1, print ribbon is used for too long, you can change the new ribbon. 2, the print head has a broken needle, drive circuit failure. The distance between the print head and the platen roller can be adjusted first. If it is still abnormal, please contact a professional for maintenance.

Fourth, the print head is blocked, stop and scream or vibrate in the same place

1. The print head guide becomes dry due to not sliding for a long time, and the print head will be blocked when it moves. You can wipe the dust off the print rails with a piece of clean paper or cloth, and then move the print head back and forth by hand to see if it can move normally. 2. The ribbon may be stuck so that the print head cannot be moved. At this time, it should be turned off immediately.

Fifth, the print content is garbled

Mostly due to poor connection between the printer and the host computer's parallel port. If this type of failure is encountered, connect the printer and the host. It may also be a driver installation error. Please select the correct driver installation. It may also be that the printer and the host cable are plugged in and the printer board is damaged.

Six, the printer does not print after sending the print job

1. Check if the printer is online. The on-line light on the printer panel should normally be on. If this indicator is off, the connection is abnormal. Please check if the printer power is on, the printer power switch is on, the printer cable is connected properly, and the paper is loaded correctly.

2. Check to see if the printer is set as the default printer. Click Start/Settings/Printer to check if there is a black tick on the currently used printer icon.

Eight, the printer indicator does not light after power on

Maintenance steps:

1, first check the AC voltage input is normal, by checking the 220V power signal line can be detected.

2. Check if the fuse of the printer power board is blown. If it blows, replace the fuse.

3. If the new replacement fuse is blown again, disconnect the device related to the 35V voltage and check for any problems with the plug.

4. Check whether the output voltage of the power board is normal. If it is abnormal, repair the circuit board.

9, the printer self-test is normal, online print is not normal

Maintenance steps:

1. Look at the "Online" light is not on. If it is not on, click the "Online" button.

2. Check that the printer is connected to the computer. Check both ends of the cable connecting the printer and the computer.

3, check the parallel port LPT settings are correct.

4, check the new software, print driver settings are correct

Ten, print writing blurred or uneven color

Maintenance steps:

1, check the print head is broken needle. If there is a blank line in the printed word, it indicates that there is a problem with the printer's print pin. Although free-software methods can be used, the speed of printing can be affected. In addition, stencils cannot be printed with a broken needle, otherwise it is easier to break other needles.

A print head price cannot be compared with the price of a print pin. A few needles were replaced with new print heads, which was too wasteful and sent to the maintenance department. You can do it yourself by following the instructions below:

1 First check the long needle or the short needle. Position the printhead's line wrap jack toward you to observe the printhead structure.

2 Remove the print head wrap and replace it with a new one. There are two wire wrappings. The upper one is the long needle and the lower one is the short needle. It is more convenient to change the long needle. Take the broken needle directly and replace it with a new one (note that the model must be the same as the broken needle). When changing the needle, the long needle must be removed, which is troublesome.

3 Ensure that the new needle replaced with the corresponding length of the old needle. The replaced print pin is used as far as possible, so that the changed pin is the same as the corresponding old pin length. If the length of the print pin is not the same after it is changed, it must be polished with fine iron sandpaper.

2, check the print signal line is broken. There are two ways to repair a signal line:

1 Find out the broken part, and use it with careful copper wire connection, but this is only expedient.

2 Buy a new pair of signal wires to replace. When replacing the printer, open the cover of the printer and remove the printed rubber roller and paper guides. Connect them as they are.

3, check the print head line package is bad. First use the multimeter's ohm file to measure the resistance of each wire package.

(Among them: No. 8-10 is a public ground wire, and the rest is a 12-pin printed wire harness. Measure the ohm range of the multimeter when measuring, measure the resistance between any other point and any point in 8-10, normal resistance value. Should be between 29 ohms and 2 ohms.)

(Where: 2-3 is a thermal device, the temperature is greater than 100 degrees Celsius does not work, less than 90 degrees Celsius to work again. 9-11 for the public ground, and the rest is a 12-pin package. The measurement method is the same as above. If the ohmic value of the wire package is out of range, the whole wire replacement package is required.