The PC cannot recognize whether the Ethernet port of dca1000 is connected or not, and it always shows that the network cable is unplugged. At the same time, both LEDs of the Ethernet interface are not on.
I have connected and configured the hardware according to the user manual, and checked the firewall and IP configuration according to the debug manual, but the situation cannot be improved. Later, I used an oscilloscope to check whether the Ethernet chip dp83867 on the dca1000 worked normally, and found that there was no correct 25m clock signal between its Xi pin and GND when powered on. This means that crystal Y2 is not working. At the same time, I measured other clock pins of dp83867, such as clk-out, and there was no clock signal. However, several power supply pins of dp83867 were measured to confirm that the chip power supply was normal. Measuring the MDC pin of the chip, I found a square wave with normal waveform, which is output by FPGA, so I think FPGA is running normally.
To sum up, I think the Ethernet chip dp83867 or crystal Y2 of dca1000 is damaged at the factory.