TP177B Serial Port Problem

I programmed my TP177B panel and interfaceed it with s7-200 CPU, every thing was fine. But when I connected a non-siemens cable to HMI, just for test purpose, HMI restarted. Now its software and displays are fine but HMI is not communicating with PLC and Field PG. I have double checked all the settings another HMI with same settings is working fine but this one is not detected. Does it mean the serial port is damaged or there is some diagnostic functionality available?

Closed cause question posted twice.

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