The LPT & IDE tester is for testing open circuit or short circuit occurs on the motherboard, hard drive IDE port and parallel port.

-  Motherboard error always shows as below: no display, fail to turn on, fail to find the hard drive or             unstable  motherboard.

-  All these problems can be tested by LPT & IDE tester.
-  As long as open circuit or short circuit can be tested, the error would be south bridge.