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21
TROUBLESHOOTING
The CML12SXXX board is fully tested and operational before shipping. If it fails to function
properly, inspect the board for obvious physical damage first. Ensure that all IC devices in
sockets are properly seated. Verify the communications setup as described under GETTING
STARTED and see the
Tips and Suggestions
sections following for more information.
The most common problems are improperly configured communications parameters, and
attempting to use the wrong COM port.
1. Verify that your communications port is working by substituting a known good serial device
or by doing a loop back diagnostic.
2. Verify option jumpers JP1 is installed and MODC is open / idle.
3. Verify Autostart is not enabled. Apply a ground level to the XIRQ signal on the
BUS_PORT and press the Reset switch. If the monitor prompts, erase the internal
EEprom by performing a BULK command or disable the Autostart by following the
procedure in the Autostart chapter.
4. Verify the power source. You should measure a minimum of 9 volts between the GND and
+VIN connections on the TB1 power connector with the standard power supply provided.
5. If no voltage is found, verify the wall plug connections to 115VAC outlet and the power
connector.
6. Verify the logic power source. You should m5 volts between the GND and +5V
connections on the TB1 power connector. If the +VIN supply is good and this supply is not
+5V, immediately disconnect power from the board. Contact
email for instructions and provide board name and problem.
7. Disconnect all external connections to the board except for COM1 to the PC and the wall
plug.
8. Make sure that the RESET line is not being held low.
Check for this by measuring the RESET Signal on the BUS_PORT.
9. Verify the presence of a 4MHz square wave at the EXTAL pin or 8MHz E clock signal if
possible.
by email for further assistance. Provide board name and
describe problem.
