What is the funtion of large chip at right on pci6023e

[auto23]

Need help troubleshooting what is damaging my PCI-6023E.  I seen burn marks on the 1"x1" chip on the right side and 1/2 way up on the board.  The inputs are not stable and when I disconnect the inputs I still see 1.5 volts.  I replace the PCI-6023E with a new board and after 1 hour I had the same thing.  Need to know what is causing it. 

[Malcolm]

Sounds like the STC (System Timing Controller) chip.  The most common cause is over voltage on the DIO lines.  What do you have hooked up to the device?  Any chance you are supplying too much voltage?  You can also use the DAQ diagnostic utility (https://www.ni.com/en/support/downloads/software-products/download.daq-diagnostic-utility.html

)  to get an idea of what board functionality is broken.

FYI: The newer M series devices have better over-voltage protection on the DIO Lines.  You should still try to prevent over voltage, but there is more margin of error.

[auto23]

Found the I/O was spiking.  Thanks