Oct 29, 2010

How to check parallel (printer/LPT) port on the motherboard?

Printer port (also called parallel/LPT port) is one of the most important port of the computer. Normally it is an on-board port of the Motherboard. That means it is integrated on the Motherboard. If your printer port gets faulty, you will not be able to take printouts as the printer will not respond on that port. In that case, you can check your parallel port by using DMM (Digital Multi Meter). Follow the steps:
  • Turn the Motherboard at the solder side. You will find the 25 pins soldered LPT port (13 + 12 in two rows).
  • Put your DMM on the "Diode" section.
  • Put the Red lead of the DMM on ground point (the most thick point) and with Black lead, check the resistance of each pin.
  • Resistance of all 13 pins (in first row) should be same and at the range of 700 Ohm to 900 Ohm.
  • Resistance of first four pins out of 12 pins (in second row) should be same as the first row (700 Ohm to 900 Ohm).
  • Other 8 pins of the second row should be grounded (0 Ohm).
  • If you find these values, that means your parallel port is working fine. If not, then you need to send the Motherboard for repairing.