1. Printer cable failure caused by printing garbled, and sometimes print the cable and its interface parts are broken or short circuit may lead to print garbled. You can run the command "dir> prn" under MS-DOS to check if the printer cable is faulty.
2. The printer hardware failure, you can use the printer self-test ( different brand printer's self-test methods are different, please refer to the printer manual) to determine whether the printer hardware failure. If the printer is really the problem, it can only repair the.
3. The printer is out of memory, when a print file is too large may also appear to print garbled, the best way is to expand the printer's memory, but this situation is rare, mostly in the early memory of the smaller printer The
4. motherboard parallel port (print port) damage caused by abnormal printing, this situation is rare, the best way is not to use parallel port printing, for a USB cable to print. Of course, if the printer or host does not have a USB interface, it can only repair or replace the motherboard.
5. I / O on the motherboard control chip damage, in fact, this situation is not difficult to distinguish, because the motherboard I / O control chip damage will often bring a lot of complications, many input and output devices will be affected. To solve only repair the motherboard!
6. Print port near the exclusion (in almost all of the motherboard can be seen) damage, sometimes due to external factors caused by changes in resistance value, then there will be printed garbled. Just replace the new exclusion, the fault can be resolved.
7. The use of switch box printing may also appear to print garbled phenomenon, replace the quality of the guaranteed switch box or do not use the switch box to print.