If two devices are set to have the same I.D., the whole chain may not work, or possibly just the conflicting devices (if you have more than two). ALWAYS make sure each device has a different I.D.(!) Most devices have jumpers or a small dial for setting the I.D. number.
Despite the reputation of being difficult to configure, I have found that SCSI is extremely easy to get up and running. Pay attention to the issues above and you should be fine. Just in case, here are a few troubleshooting tips:
Check Termination First. Then check it again.
Check I.D.#s
Use quality cables. If you have a problem, especially with a fast hard drive, try changing the cable.
Use the shortest connections possible. Pay attention to the maximum total length. No more than 1 meter (=3.5 feet).
Make sure the cables are plugged in correctly and firmly: pin 1 to pin 1.
