Nano ethernet port stopped working - no link led

I think this may be a hardware issue. Nano is pretty new, 1-2 weeks old, so probably easiest to just exchange on amazon, just want to make sure i’m not missing anything. Has been working fine up until now. It’s on a private network. I woke up this morning and couldn’t ssh into it. It’s headless.

I tried to power cycle it a couple times, then plugged in a usb cable to my laptop and got it up on serial console. It sees the ethernet card, but no link detected, nor link light. I tried a different switch port, a different cable and verified with my laptop that the cable and switch port are fine.

I’m not sure if the link led ever worked, but i’m not seeing link on the switch either.

any other troubleshooting steps? I should see? see output of lspci, dmesg, and ethtool below.

$sudo lspci -v
00:02.0 PCI bridge: NVIDIA Corporation Device 0faf (rev a1) (prog-if 00 [Normal decode])
        Flags: bus master, fast devsel, latency 0, IRQ 84
        Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
        I/O behind bridge: 00001000-00001fff
        Memory behind bridge: 13000000-130fffff
        Capabilities: [40] Subsystem: NVIDIA Corporation Device 0000
        Capabilities: [48] Power Management version 3
        Capabilities: [50] MSI: Enable- Count=1/2 Maskable- 64bit+
        Capabilities: [60] HyperTransport: MSI Mapping Enable- Fixed-
        Capabilities: [80] Express Root Port (Slot+), MSI 00
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [140] L1 PM Substates
        Kernel driver in use: pcieport

01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
        Subsystem: Realtek Semiconductor Co., Ltd. RTL8111/8168 PCI Express Gigabit Ethernet controller
        Flags: bus master, fast devsel, latency 0, IRQ 406
        I/O ports at 1000 [size=256]
        Memory at 13004000 (64-bit, non-prefetchable) [size=4K]
        Memory at 13000000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: [40] Power Management version 3
        Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [70] Express Endpoint, MSI 01
        Capabilities: [b0] MSI-X: Enable- Count=4 Masked-
        Capabilities: [d0] Vital Product Data
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [140] Virtual Channel
        Capabilities: [160] Device Serial Number 00-00-00-00-00-00-00-00
        Capabilities: [170] Latency Tolerance Reporting
        Capabilities: [178] L1 PM Substates
        Kernel driver in use: r8168


$ dmesg |grep -i eth
[    0.000000] psci: probing for conduit method from DT.
[    4.354485] igb: Intel(R) Gigabit Ethernet Network Driver - version 5.4.0-k
[    4.399949] r8168 Gigabit Ethernet driver 8.045.08-NAPI loaded
[    4.420365] r8168 0000:01:00.0 (unnamed net_device) (uninitialized): Invalid ethernet address 00:00:00:00:00:00, trying device tree node
[    4.432749] r8168 0000:01:00.0 (unnamed net_device) (uninitialized): Found valid ethernet address 00:04:4b:ea:bc:b2 from device tree
[    4.528756] usbcore: registered new interface driver cdc_ether
[    8.902922] using random self ethernet address
[    8.907399] using random host ethernet address
[   10.008655] using random self ethernet address
[   10.016799] using random host ethernet address
[   11.377086] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   11.378217] eth0: 0xffffff800a36e000, 00:04:4b:ea:bc:b2, IRQ 406
[   11.439113] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[   17.587538] Bluetooth: BNEP (Ethernet Emulation) ver 1.3



$ sudo ethtool eth0
Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: Symmetric Receive-only
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: Unknown
        Supports Wake-on: pumbg
        Wake-on: g
        Current message level: 0x00000033 (51)
                               drv probe ifdown ifup
        Link detected: no

So i have a usb network adapter for one of my laptops i plugged it into the jetson and it worked right away.

Leaning heavily towards hardware issue.

Could you try a empty sdcard and reflash the whole board with sdkmanager? We should reset the software to default status first before saying this is hardware issue.