Troubleshooting Tips 5-11
Troubleshooting Tips
Review these tips to check the 3C509B NIC further.
1 Make sure the NIC is seated correctly in the slot.
Check the installation by reviewing the installation 
instructions in Chapter 2.
2 Inspect all cables and connections.
If you are using thin Ethernet cable, make sure that you 
have a T connector attached to the NIC and all other NICs 
on the network. Make sure that the thin Ethernet segment 
is terminated at both ends with a 50-ohm terminator.
3 Make sure that you booted your computer under 
DOS version 3.1 or later, and that no device drivers 
or memory managers are loaded.
4 If you are running the Group 2 test (only on the 
3C509B-TPC or the 3C509B-COMBO NIC), make sure 
that the loopback plug is securely attached to the 
NIC’s BNC connector and that the NIC is attached to 
a properly cabled network.
If this test fails, try another loopback plug.
5 If you are running the Group 3 test, make sure 
that the NIC is connected to a properly cabled and 
inactive network and that an echo server is set up 
on the network.
To further isolate the problem, use a crossover cable 
to connect a known good PC to the PC you are testing. 
The PCs should be connected back to back with no 
other network devices between the PCs. For more 
information about the crossover cable, see “Crossover 
Cable Troubleshooting Tips.”
6 Make sure that the settings for the NIC’s options are 
not the same settings used in the system or on any 
other NIC installed in the computer.
If you need help, select Configuration and Diagnostic 
Program from the EtherDisk diskette main menu. Then 
select Commonly Used Interrupts or I/O Base Addresses 
from the NIC Configuration screen.