The diagnosis method varies depending on the OS version of the XTOP product.
You can check the OS version in the [Menu Screen] - [Information] section of the XTOP product.
For instructions on how to access the menu screen, please refer to post number 3 on the [A/S Support] board.

 

If the OS version of the XTOP product is V3.1:
Short pins 2 and 3 of the COM2 RS-232C connector using a clip or similar tool, then start [COM2 Port Self Diagnosis] (item 8 in the [Diagnostics] menu) from the menu screen. The [COM2 PORT DIAG.] window will pop up, and if [OK] appears in result item 3, the port is functioning normally.
If you have properly shorted the pins but result item 3 shows [COM2 Port/Connection Error!], it is likely a hardware issue, and you should contact the customer support center for service.

 

If the OS version of the XTOP product is V4.8:
Short pins 2 and 3 of the COM2 RS-232C connector using a clip or similar tool, then run [COM2 Loopback Diagnosis (Rx-Tx Pin Connection)] from the [Device Manager] menu on the menu screen.
The COM2 Loopback Diagnosis window will pop up. If [OK] appears in result item 3, the port is functioning normally.
If you have properly shorted the pins but result item 3 shows [Time Out Error], it is likely a hardware issue, and you should contact the customer support center for service.

 

Additional Notes:
If you use a tester, connect pin 5 to the tester's negative terminal and pin 3 to the positive terminal. If the measured voltage is about -5.56V, the port is normal.
For the 9-pin D-SUB connector, the pin numbers are as follows: from the top left to the right: 5, 4, 3, 2, 1; from the bottom left to the right: 9, 8, 7, 6