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Loopback Test Plugs & Diagram:

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We Listen To Our Customers and this is what they have said: Our customers have asked us to include additional more practical PC testing tools in our Professional Technicians Kits other then loopback test plugs most do not use to keep the  cost of our kits down.

Enlarge View! PC Certify Loopback Plug Set

Loopback Plug Set Diagram:

These plugs are simple to build so we have included a diagram so you can build your own Serial, Parallel Port and Printer Port test   Loopback   plugs if you require them. Loopbacks are used to test and diagnose if your ports are working correctly. You can find Loopback plugs on line at companies such as L-Com and there are many other companies out there as well.

Parallel Port, Serial Port and Printer Port external loopback testing requires the following plugs below.

Loopback Plug Wiring Diagrams connect pins as follows:

  Serial Loopback Plug, DB9 female, connect 9 Pin
  02 to 03
  07 to 08
  01 to 04 to 06 to 09

Parallel Loopback Plug, DB25 Male, connect 25 Pin
02 to 03
04 to 05
6 to 08 to 20 to 22

Printer Loopback, connect wrap plug pins
01 to 13
02 to 15
10 to 16
11 to 17
12 to 14