I have a problem when working with a virtex-7 xilinx fpga: although all the connections are correct and the setup is reliable, it fails in chaining step in the impact. it is worth to mention that I test in the same manner by another fpga and everything is OK. My test show an impedance of 3 Kilo Ohms between TDO pin and GND while this quantity is about 800 Kilo Ohms in a proper fpga of the same model. This is the only difference observed between the damaged fpga and the proper one. -I'd like to know if we can conclude this pin has been damaged? - Could it be repaired anyway? - Is there any other solution to chain and debug this fpga?