PCIE issue in DM8168EVM board

Hello,

I found the pcie interface can't work normally now, which can't detect the device(RTL8111C） nic which works well in other board).

SW5-1 (PCIe RST) switch was set to OFF.(near PCIE SLOT)

when power on ,there is nothing output from the serial port.

But when I unplug RTL8111C,then power on,the board works normally.