Hi,

I am very new to electronic circuits and was wondering if anyone had any advice with troubleshooting an old CPU board. The board gives a communication error when using the serial port. The RS232 port seems to be working fine as does the MAX232 when looking at the voltages. Any advice would be extremely appreciated. Thanks

 

What board? What error?

 

The Board is a CPU369 (https://www.fujitsu.com/downloads/MICRO/fma/pdfmcu/app_ug-910011-15-flex-fpga-eva-kit-369.pdf)
The error I get is an invalid communication status