NEC Versa LX User Manual page 73

Serial device does not work
Parallel device does not work
7-4 Troubleshooting
Check if device driver is installed properly.
Check if serial device is connected properly.
Check the device drive installation for any IRQ or I/O
address conflict.
Replace serial device.
Check the I/O controller chip on the main board for any
cold or loose soldering.
Replace the I/O board.
Check all connections.
Check if external device is turned on.
Check the device drive installation for any IRQ or I/O
address conflict.
Test another parallel device.
Check I/O controller chip on the main board for any
cold or loosed soldering.
Replace the I/O board.