Diagnostic Testing Under Windows 3.x 6-3Follow these steps to run the Group 1 tests:1 From the Test menu, select Run Tests and press Enter.The Run Tests dialog box appears with the Start buttonalready selected.2 Press Enter to start the tests.Group 1 tests run 10 times (default setting) unless you specifyotherwise. The test results are displayed in the Results column.Running the Group 2 TestThe Group 2 test is the Network Loopback Test. It tests whetherthe 3C509B-COMBO and 3C509B-TPC NICs can transmit andreceive data over thin Ethernet coaxial wire. This test requireseither installing a loopback plug at the transceiver connectionon the NIC or running the test on an idle network.A failure in this test usually indicates a cabling problem.CAUTION: Running the Group 2 test while connected to an activenetwork can cause intermittent failures.Assembling a Loopback PlugIf you do not have a loopback plug, you can order one from yourauthorized network supplier or you can make your own. You canpurchase the terminators from your network supplier (3Com partnumber 3C535).To assemble the loopback plug, connect two 50-ohm networkcable terminators to a T connector, as shown in Figure 6-1.Figure 6-1 Assembling a Loopback Plug50Ω Terminator50Ω TerminatorT connector
