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AC68U Lan Ports not working

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Rajesh

Occasional Visitor
I have AC68u running on Merlin FW (Vx.384.17), out of blue all the lan ports including WAN port are not working (Wifi is fine though) not sure what went wrong.

Code:
admin@RT-AC68U-D698:/tmp/home/root# robocfg show
Switch: enabled
Port 0:   DOWN enabled stp: none vlan: 2 jumbo: off mac: 00:00:00:00:00:00
Port 1:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 2:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 3:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 4:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 5: 1000FD enabled stp: none vlan: 2 jumbo: off mac: 60:45:cb:67:d6:98
Port 7:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
Port 8:   DOWN enabled stp: none vlan: 1 jumbo: off mac: 00:00:00:00:00:00
VLANs: BCM5301x enabled mac_check mac_hash
   1: vlan1: 1 2 3 4 5t
   2: vlan2: 0 5

I reverted to asus firmware which didn't help. Any pointers will be greatly appreciated.

Thanks
Rajesh
 
Try a hard reset by holding the reset and WPS buttons at the same time, then applying power and waiting until the LED lights flash in unison (may take a few seconds). Then power off and back on normally. May take several attempts. If that doesn't work, perhaps the switch is physically dead.
 
I did this but nothing changed
Just to be clear, did you read the instructions for hard reset in the link for your specific router and follow them? If you really did that and nothing's changed, then next you should try finding a replacement power brick, from the same router model if possible.
 
Just to be clear, did you read the instructions for hard reset in the link for your specific router and follow them? If you really did that and nothing's changed, then next you should try finding a replacement power brick, from the same router model if possible.
Yes @Zetto, I clearly followed the instructions mentioned in [Wireless] ASUS router Hard Factory Reset - Method 1 | Official Support | ASUS Global but nothing changed. Am guessing it has indeed bricked.
 
try another power adapter, if you can find one. There's a slight chance maybe it is causing issues.
 
I have a same or similar issue. All four LAN ports and the WAN port are not working on one of my RT-AC66U B1. It happened all of a sudden. I thought there might have been a powerspike or something killing the ports but it wasn't the season for that thunderstorms.

I have tried reset, hard reset, different stock-fw and merlin 386.4

Is there anything else that I could try?
 
I have a same or similar issue. All four LAN ports and the WAN port are not working on one of my RT-AC66U B1. It happened all of a sudden. I thought there might have been a powerspike or something killing the ports but it wasn't the season for that thunderstorms.

I have tried reset, hard reset, different stock-fw and merlin 386.4

Is there anything else that I could try?

Besides trying a different AC/DC power adapter, leave it ON and unplug the adapter from the building power and let it chill out a good while. Also disconnect everything else connected to it. Maybe such power cycle/drain voodoo will affect it.

OE
 
All ports suddenly not working is not a good sign. I would say hardware failure.
 
Whats the theory behind this? I can imagine that a different adapter might give different voltage but why would the adapter plugged into the router but not the wall change anything?
The device has been in a box for some months unplugged so from that perspective it should have had time to chill.

But no idéas about any interesting nvram setting that might make a mess?

I had another issue with another AC66U-B1 that did not connect as an AIMesh node. Turned out it was a setting in nvram that caused it. This thread helped me fix it. https://www.snbforums.com/threads/66u_b1-firmware-updated-now-cant-be-added-as-aimesh-node.67581/
 
All ports suddenly not working is not a good sign. I would say hardware failure.
yes, I also think thats the most likely reason but since everything else works (or at least wifi..) I thought it was worth looking into if might be fw or setting related.
I read something about some powersave feature that caused certain ports to be disabled but couldn't find any specifics. Is there some documentation on what the firmware settings do?

if the whole thing was fried or one port didn't work it would be more logical. Ive had both those things happen at thunderstorms.
 
Last edited:
Whats the theory behind this? I can imagine that a different adapter might give different voltage but why would the adapter plugged into the router but not the wall change anything?
The device has been in a box for some months unplugged so from that perspective it should have had time to chill.

No theory... just letting the (marginal) circuits deactivate fully... which you've done. It's been mentioned around here before.

Otherwise, it's likely dead and no firmware setting can recover that.

FYI, using a UPS will show that bad power can happen anytime, no just during a weather event.

OE
 
Are you running any Ethernet outdoors like to a garage or external security camera? If so, are you using shielded cable and connectors? A cable can act like an antenna and pickup induced voltages.
 
Are you running any Ethernet outdoors like to a garage or external security camera? If so, are you using shielded cable and connectors? A cable can act like an antenna and pickup induced voltages.
Yes, one unshielded cable about 50 meters through an old waterpipe (copper) to another house. But this device was not connected there when it stopped working, it might have been earlier. Could any damage be delayed?Feels unlikely..?
I have had other equipment fried byt this before so i try real hard to unplug the cables when theres thunderstorms.
Would it help with a shielded cable? I know there are plugs you can connect as protrection and I tried one but it didn't work, as in no traffic coming through..
 
I have a same or similar issue. All four LAN ports and the WAN port are not working on one of my RT-AC66U B1. It happened all of a sudden. I thought there might have been a powerspike or something killing the ports but it wasn't the season for that thunderstorms.

I have tried reset, hard reset, different stock-fw and merlin 386.4

Is there anything else that I could try?
Buy a new router.
 
Yes, one unshielded cable about 50 meters through an old waterpipe (copper) to another house.

Does that Ethernet cable terminate in equipment on separate AC power and Earth Ground in the other building?

OE
 
Buy a new router.
yup. I did. But since this works with Wifi Im going to use it as wifi-repeater if i have to. Just thought it might be worth looking into if it might be firmware/setting related..
 
Does that Ethernet cable terminate in equipment on separate AC power and Earth Ground in the other building?

OE
Hmm, good question. I guess there should be separate grounding for each house/main central.

It should be the same but it's an old system (houses build 1850ies, electrified 1938, partly renovated in the 1960ies, 80ies and 2012. So there might be strange things in there. I know I have one phase that is quite a lot higher loaded than the other.

That is worth investigating more in any case.. Should get it up on my prio-list...
 

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