If your having a serial port problem, it's most likely a system resource conflict. System resource conflicts include problems such as a serial device that fails intermittently or doesn't work at all, another device that stops working when the serial device is installed, or the PC locking up during the boot sequence. The test requires that you know how to troubleshoot various situations, and you may encounter one on troubleshooting a serial port. To determine the source of the problem, check the following. |
Inspect the port for bent pins. Certain pins absolutely must be straight in order for the device to work properly. |
Ensure that the cable is the appropriate cable for the device. Some serial devices can't use a straight through or null modem cable. |
| Check the Windows Device Manager for system resource conflicts. An IRQ conflict is the most common error in this area. Remember, only one customer (device) to an IRQ at a time.
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Be sure that the serial cable is not more than 50 feet long. Beyond this distance, you can lose data integrity, which shows up any number of ways, none of which are good. |